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DM6420 Driver for Linux User`s Manual Version 2.01.xx

1. 10_request mask OxFFIF DM6420 Driver for Linux 94 Stop pacer clock by software trigger io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request SetTriggerPolarity6420 int SetTriggerPolarity6420 int descriptor enum DM6420HR_POLAR Polarity Description Select which edge of an external pacer clock triggers a board s burst mode Parameters descriptor File descriptor from OpenBoard6420 call Polarity Which external pacer clock edge triggers burst mode Valid values are DM6420HR_POLAR_POSITIVE and DM6420HR_POLAR_NEGATIVE Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Polarity is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Trigger Mode Register at base I O address 6 10_request reg r_TRIGGER_6420 Only change bit 12 in register 10_request mask OXEFFF mo 26420 Driver for Linux Set external trigger to occur on negative edge 10_request value 1 lt lt 12 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request SetTriggerRepeat6420 int SetTriggerRepeat6420 int descriptor enum DM6420HR_REPEAT Repeat Description Select whether or not a trigger initiates multiple A D conversion cycles Parameters descriptor File descriptor from OpenBoard6420 call Repeat
2. GetIRQCounter6420 int GetIRQCounter6420 int descriptor enum DM6420HR_INT IRQChannel unsigned long counter_value_p Description Get the number of interrupts that have occurred on a board s specified interrupt circuit Data returned from this function is interpreted differently depending upon usage of the force argument on the insmod command If you specify a nonzero value for the force argument the value returned represents the number of interrupts that occurred since the driver module was loaded If you specify a zero value for the force argument or do not use force at all the value returned represents the number of interrupts that occurred since the device file was opened Parameters descriptor File descriptor from OpenBoard6420 call IRQChannel Interrupt circuit to read counter value from Valid values are DM6420HR_INT1 and DM6420HR_INT2 Counter_value_p Address where counter value should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access EINVAL IRQChannel is not valid EINVAL No IRQ was ever allocated to IRQChannel DM6420 Driver for Linux 48 IOCTL Interface int rc struct DM6420HR_GIC io_request Target of operation is first interrupt circuit io_request intr DM6420HR_INT1 Any value works here because it is ignored making this request However on return from ioctl the
3. ClearIRQ16420 int ClearIRQ16420 int descriptor Description Clear the second interrupt circuit on a board Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_IRQ72 ClearRegister6420 int ClearRegister6420 int descriptor u_int16_t ClearValue Description Write a bit mask into a board s Program Clear Register and then read from the Clear Register to clear some part s of the board Other library functions make use of this routine to perform their work Parameters descriptor File descriptor from OpenBoard6420 call ClearValue Bit mask to write into Program Clear Register before reading Clear Register Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access Wo DM6A20 Driver for Linux IOCTL Interface int rc Clear the contents of board s channel gain table rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_CLEAR_GAIN ClockDivisor6420 int ClockDivisor6420 int descriptor enum DM6420HR_CLK Timer u_int16_t Divisor Description Set the divisor for the specified counter on the 8254 chip Before calling this function the counter must have been
4. i0_request value 0x0004 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request 8726420 Driver for Linux SetIRQ1Source6420 int SetIRQ1Source6420 int descriptor enum DM6420HR_INTSRC IRQSource Description Select the interrupt source of the second interrupt circuit on a board Parameters descriptor File descriptor from OpenBoard6420 call IRQSource Source of interrupt on first circuit Valid values are IRQS_AD_SAMPLE_CNT_6420 IRQS_AD_START_CONVERT_6420 IRQS_AD_END_CONVERT_ 6420 IRQS_AD_WRITE_FIFO_6420 IRQS_AD_FIFO_HALF_6420 IRQS_AD_DMA_DONE_ 6420 IRQS_RESET_GAIN_TABLE_6420 IRQS_PAUSE_GAIN_TABLE_6420 IRQS_EXT_PACER_CLOCK_ 6420 IRQS_EXT_TRIGGER_6420 IRQS_DIGITAL_6420 IRQS_TC_COUNTERO_6420 IRQS_TC_COUNTERO_INVERTED_ 6420 IRQS_TC_COUNTER1_ 6420 IRQS_DIO_FIFO_HALF_6420 and IRQS_DIO_WRITE_FIFO_6420 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL IRQSource is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Interrupt Register at base I O address 8 a i0_request reg r_IRQ_ 6420 Only change bits 8 through 12 in register or DM6420 Driver for Linux 88 10_request mask OxEOFF Set interrupt source to be User Timer Counter 0 countdown to zero i0_request value OxB lt lt 8 rc ioc
5. 2 i0_request reg r_ STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 6B 2M6420 Driver for Linux Tf bit 11 is set in Status Register then digital input FIFO is not half full Tf bit 11 is cleared then digital input FIFO is half full t if io_request value amp 0x0800 fprintf stdout Digital input FIFO is not half full n IsFirstADDMADone6420 int IsFirstADDMADone6420 int descriptor int ad_first_dma_done_p Description Determine whether or not a board s A D first DMA transfer is complete when in dual channel DMA mode NOTE The description of the ad_first_dma_done_p parameter below is based upon the hardware manual s description of the First DMA Flag in the Status Register However the manual erroneously provides an inverted interpretation of this flag Since this function examines the First DMA Flag the value stored in ad_first_dma_done_p is inverted also In reality the value stored in this address will be zero if A D first DMA transfer is finished and nonzero otherwise Parameters descriptor File descriptor from OpenBoard6420 call Ad_first_dma_done_p Address where A D first DMA done flag should be stored If A D first D
6. Interrupt circuit to enable Valid values are DM6420HR_INT1 and DM6420HR_INT2 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL IRQChannel is not valid DM6420 Driver for Linux 42 IOCTL Interface int rc struct DM6420HR_IE io_request Target of operation is first interrupt circuit io_request intr DM6420HR_INT1 Enable the interrupt circuit i0_request action 1 rc ioctl descriptor DM6420HR_IOCTL_IRQ ENABLE amp io_request EnableTables6420 int EnableTables6420 int descriptor int Enable_AD_Table int Enable_Digital_Table Description Enable or disable the A D and digital tables in the channel gain scan memory on a board Parameters descriptor File descriptor from OpenBoard6420 call Enable_AD_Table Flag to indicate whether the A D table should be enabled A value of 0 means disable the A D table A nonzero value means enable the A D table Enable_Digital_Table Flag to indicate whether the digital table should be enabled A value of 0 means disable the digital table A nonzero value means enable the digital table Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EOPNOTSUPP The digital table is to be enabled but the A D table is to be disabled 43 DM6420 Driver for Linux IOCTL
7. IsFirstADDMADone6420 StartDMA6420 StopDMA6420 General ClearBoard6420 ClearRegister6420 CloseBoard6420 InitBoard6420 LoadControlRegister6420 OpenBoard6420 ReadStatus6420 11 DM6420 Driver for Linux Interrupt Control and Status ClearIRQ06420 ClearIRQ16420 DisableIRQ6420 EnableIRQ6420 GetIRQCounter6420 InstallCallbackIRQHandler6420 LoadIRQRegister6420 RemoveIRQHandler6420 SetIRQOSource6420 SetIRQ1Source6420 Timer Counter Control and Status ClockDivisor6420 ClockMode6420 DoneTimer6420 IsBurstClockOn6420 IsPacerClockOn6420 ReadTimerCounter6420 SelectTimerCounter6420 SetBurstClock6420 SetPacerClock6420 SetPacerClockSource6420 SetSampleCounterStop6420 SetUserClock6420 DM6420 Driver for Linux 12 Alphabetical Function Listing ChannelGainDataStore6420 int ChannelGainDataStore6420 int descriptor int Enable Description Enable or disable a board s channel gain data store Parameters descriptor File descriptor from OpenBoard6420 call Enable Flag to indicate whether the channel gain data store should be enabled A value of 0 means disable the data store A nonzero value means enable the data store Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to the Control Register at I O base address 2 io_request reg r
8. CONTROL_6420 Only change bit 4 in the Control Register a 10_request mask OXFFEF Enable the channel gain data store io_request value 1 lt lt 4 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request 13 DM6420 Driver for Linux ClearADDMADone6420 int ClearADDMADone6420 int descriptor Description Clear a board s A D DMA done flag Parameters descriptor Return Value 0 1 EACCES IOCTL Interface int rc File descriptor from OpenBoard6420 call Success Failure with errno set as follows descriptor refers to a file that is open but not for write access rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_AD_DMA_DONE ClearADFIFO6420 int ClearADFIFO6420 int descriptor Description Clear a board s A D sample FIFO Parameters descriptor Return Value 0 1 EACCES IOCTL Interface int rc File descriptor from OpenBoard6420 call Success Failure with errno set as follows descriptor refers to a file that is open but not for write access rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_AD_ FIFO DM6420 Driver for Linux 14 ClearBoard6420 int ClearBoard6420 int descriptor Description Reset a board Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not fo
9. DM6420 Driver for Linux 46 Parameters descriptor File descriptor from OpenBoard6420 call Dma_buffer_p Address of user buffer DMAChannel DMA circuit to operate on Valid values are DM6420HR_DMAI and DM6420HR_DMA2 Length Number of bytes to transfer Offset Offset in bytes from beginning of driver s DMA buffer where read should begin Bytes_transferred_p Address where actual number of bytes transferred will be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access EFAULT dma_buffer_p is not a valid user address EFAULT dma_buffer_p is not large enough to hold the data EINVAL DMAChannel is not valid EINVAL No DMA channel was ever allocated to DMAChannel EINVAL No DMA buffer was ever allocated to DMAChannel EINVAL length offset lies beyond the end of the driver s DMA buffer IOCTL Interface int rc struct DM6420HR_GDD io_request intl6_t user_buffer 8192 Read from DMA buffer on second DMA circuit io_request dma DM6420HR_DMA2 Transfer data into user_buffer array io0_request buf void amp user_buffer 0 47 DM6420 Driver for Linux Transfer 8192 16 bit values 16384 8 bit values io_request length 16384 Read from beginning of driver s DMA buffer i io_request offset 0 rc ioctl descriptor DM6420HR_IOCTL_DMA_GETDATA amp io_request
10. Interface int rc struct DM6420HR_MIO16 io_request Write to Control Register at base I O address 2 ai io_request reg r CONTROL_6420 Only change bits 2 and 3 in Control Register 10_request mask OxFFF3 Enable just the A D table To disable both tables set io_request value to 0 To enable both tables set io_request value to 0x3 lt lt 2 io_request value 1 lt lt 2 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request GetAutoincData6420 int GetAutoincData6420 int descriptor enum DM6420HR_STR_Regs from_register enum DM6420HR_STR_TYPE type void buffer_p size_t element_num ys Description Initiate a streaming read from a board Once can specify the board register to read from what size data is to be transferred and how many data elements to transfer Parameters descriptor File descriptor from OpenBoard6420 call From_register Register from which the data should be read Valid values are rSTR_AD_6420 and rSTR_DIN_FIFO_6420 DM6420 Driver for Linux 44 Type Type size of element to be transferred Valid values are DM6420HR_STR_TYPE_BYTE and DM6420HR_STR_TYPE_WORD Buffer_p Address of buffer in which to place the data read Element_num How many data elements of type type should be read Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read acce
11. Linux 84 IOCTL Interface int rc struct DM6420HR_IO16 io_request Before loading channel gain latch bits 1 and 0 in Control Register at base T O address 2 must be set to zeroes This is not shown here Write to Load Channel Gain Latch Register at base I O address 4 i0_request reg r CHANNEL_GAIN_ 6420 Target of operation is analog input channel 7 i0_request value 0x0006 Set x2 gain y io_request value l 1 lt lt 4 ok Set differential mode io_request value l 1 lt lt 9 rc ioctl descriptor DM6420HR_IOCTL_OUTW amp io_request SetConversionSelect6420 int SetConversionSelect6420 int descriptor enum DM6420HR_CONV Select Description Configure how a board s A D conversion is done Parameters descriptor File descriptor from OpenBoard6420 call gS ts 26420 Driver for Linux Select Indicates how A D conversions are controlled Valid values are DM6420HR_CONV_SOFT_TRIGGER DM6420HR_CONV_PACER_CLOCK DM6420HR_CONV_BURST_CLOCK and DM6420HR_CONV_DIGITAL_INT Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Select is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Trigger Mode Register at base I O address 6 io_request reg r_TRIGGER_6420 Only change bits 0 and 1 in
12. O E E 10 DIGITAL TO ANALOG CONVERSION ccscscssssssssssssssscsssssssssssssssssssseeeeseseseeeeeeseeseseeeeeseeeeasaeaeees 10 DIGIPAL Of secev cite cette eed bath etal MME Bat al Sal ested dial Ate settle anbeatl ceeame da dl wl ih 11 DIRECT MEMORY ACCESS DMA DATA TRANSFER csesssceeesnseecseneeeeseneeeesssuaeseseneesensseeenees 11 EIAN E ESAN EREE E E A EEE E E E EEES 11 INTERRUPT CONTROL AND STATUS cccccscssssssssscsssssssssssssssssssssssssessseeeseesseeesessseseseeseaeeeaeaeaeeaees 12 TIMER COUNTER CONTROL AND STATUS cccccsssesssssssssssssssssssssssssssssssssssssceesseseesesssseeeseseaeeeees 12 ALPHABETICAL FUNCTION LISTING eeesesssesoosesssssooosesseessoosossssssooooseessesooosesssessooseessssoo 13 EXAMPLE PROGRAMS REFERENCE cscscssssssssssssssscccssssssscccccccsscssssscsscccsscsssssscsesoees 101 LIMITED WARRAN EY ess isccccsiascccesesccassssuecdssouscacessacdeasonetacssseasdcdsenssdecnssosteusesesedsasesseuasecesueces 102 DM6420DriverforLinux ss o w Introduction This document targets anyone wishing to write Linux applications for an RTD DM6420 analog T O dataModule It provides information on building the software and about the Application Programming Interface used to communicate with the hardware and driver Each high level library function is described as well as any low level ioctl system call interface it may make use of The diagram below 1 provides a general overview of what hardwar
13. OUT OF THE USE OR INABILITY TO USE THE PRODUCT SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR CONSUMER PRODUCTS AND SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE DM6420DriverforLinux gt gt w RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 USA Our website www rtd com 03 M6420 Driver for Linux
14. Parameters descriptor File descriptor from OpenBoard6420 call Digital_interrupt_p Address where digital interrupt flag should be stored If an advanced digital interrupt has occurred a nonzero value will be stored here Otherwise 0 will be stored here 926420 Driver for Linux Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 ah 10_request reg r_ STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 Tf bit 9 is cleared in Status Register then no digital interrupt occurred Tf bit 9 is set then digital interrupt occurred ai if io_request value amp 0x0200 0 fprintf stdout Digital interrupt has not occurred n IsDINFIFOEmpty6420 int ISDINFIFOEmpty6420 int descriptor int digital_fifo_empty_p Description Determine whether or not a board s digital input FIFO is empty DM6420 Driver for Linux 60 Parameters descriptor File descriptor from OpenBoard6420 call Digital_fifo_empty_p Address where digital FIFO empty flag should be stor
15. member variable counter contains the interrupt count il 10_request counter 0 rc ioctl descriptor DM6420HR_IOCTL_GET_IRQ_ COUNTER amp io_request if re 1 fprintf stdout Interrupt count ld n io_request counter InitBoard6420 int InitBoard6420 int descriptor Description Initialize a board This will 1 clear the board 2 clear the A D DMA done flag 3 clear the channel gain table and 4 clear the A D input FIFO Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface This function makes use of several ioctl requests 49 DM6420 Driver for Linux InstallCallbackIRQHandler6420 int InstallCallbackIRQHandler6420 int descriptor void callback void enum DM6420HR_INT IRQChannel Description Install a function which will be called whenever an interrupt occurs and the driver sends a signal to the process to indicate that the interrupt happened Parameters descriptor File descriptor from OpenBoard6420 call Callback Address of callback function IRQChannel Board interrupt circuit that signal should be attached to Valid values are DM6420HR_INT1 and DM6420HR_INT2 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for
16. of PC 104 Consortium All other trademarks appearing in this document are the property of their respective owners ii 2M6420 Driver for Linux Table of Contents FABLE OB CONTENTS ieivcsccscssintcccsossscessssscdsenescccsceeetcedensiccesdecssesbacedeudacsontuedesesunedesduscedesessacessese 4 INTRODUCTION civsiscisctistisbeasebevccossesedicsssdacsteutesdesseseeccosselectcusscsssdeelesbessetescisssoietisecscossbsateebessesese 5 INSTALLATION INSTRUCTION cccsssssssssscccsssscccsssscccessscccssssccsesssscccsssscccessssesessssssceees 6 EXTRACTING THE SOFTWARE ode ccce acta a NE tia cdevesveesils dete Seue A AE 6 CONTENTS OF INSTALLATION DIRECTORY c cccsssssssssssssssssssssssssssssssssssssssseesaeeseseseseeeeeseeaeeeeeees 6 BUIEDING THE DRIVER ssecs2ecccossti cies cee coee cic a Sed cada ouebee n one cousll aaa er 6 BUIEDING THE LIBRARY irainei asn a adaa anea e o anid iea Tar aKo T Ka Eror aKa 7 BUILDING THE EXAMPLE PROGRAMS cccccscssssssscsssssescscssssssssssssssssssseeeseseessusaeeseseeeeeeeeusesaeeeeeees 7 USING THE API FUNCTIONG ccccsssscssssscccsssscccsssscccssscccessscccssssccsesssscccsssscsssssesesesssscsesees 8 FUNCTION REFERENCE sicccssssscssscsssccsvsessccsssnscocesssseccssvansccessensccvevacsscuseessesossesseetesssessssessecsseeses 9 API FUNCTION GROUPS issccccisssscsossessscessetacsesiensssedbecsseesdessscesbesossesseseesessesddoossessccesdesecsessesessess 10 ANALOG TO DIGITAL CONVERSION irori e EE
17. read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 10_request reg r_ STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents ai io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 DM6420 Driver for Linux 54 Tf bit 4 is set in Status Register then A D DMA is done ok Tf bit 4 is cleared then A D DMA is not done if io_request value amp 0x0010 fprintf stdout A D DMA completed n IsADFIFOEmpty6420 int IEADFIFOEmpty6420 int descriptor int ad_fifo_empty_p Description Determine whether or not a board s A D FIFO is empty Parameters descriptor File descriptor from OpenBoard6420 call Ad_fifo_empty_p Address where FIFO empty flag should be stored If the A D FIFO is empty a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 gi io_request reg r_STATUS_6420 Any value works here because it is ignored making this request However on return from
18. read access IOCTL Interface int rc struct DM6420HR_IO16 io_request 6 DM6420 Driver for Linux Read from Status Register at base I O address 2 10_request reg r STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents 2 i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 Tf bit 7 is set in Status Register then A D pacer clock gate is on If bit 7 is cleared then pacer clock gate is off t if io_request value amp 0x0080 fprintf stdout A D pacer clock gate is on n LoadADSampleCounter6420 int LoadADSampleCounter6420 int descriptor u_int16_t NumOfSamples Description Load a board s analog to digital sample counter Parameters descriptor File descriptor from OpenBoard6420 call NumOfSamples Number of samples to take Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface This function makes use of several ioctl requests DM6420 Driver for Linux 66 LoadADTable6420 int LoadADTable6420 int descriptor u_intl6_t ADEntries ADTableRow ADTable_p Description Load a board s A D table with the given number of entries Parameters descriptor File descriptor from
19. see the following message Warning loading rtd dm6420 o will taint the kernel no license You can safely ignore this message since it pertains to GNU General Public License GPL licensing issues rather than to driver operation The final step is to create dev entries for the hardware Previous versions of the driver always assumed a character device major number of 240 when registering the boards and creating the dev entries Instead the driver now asks the kernel to dynamically assign a major number Since this major number may change each time you load the driver the best way to create the device files is to use the command make devices this generates four files in dev named rtd dm6420 0 through rtd dm6420 3 If you ever need to unload the driver from the kernel you can use the command make rmmod Building the Library The example programs and your application use the DM6420 library so it must be built before any of these can be compiled To build the library change your current directory to lib and issue the command make The GNU C compiler gcc is used to compile the library source code The DM6420 library is statically linked and is created in the file librtd dm6420 a Building the Example Programs The example programs may be compiled by changing your current directory to examples and giving the command make which builds all the example programs If you wish to compile a subset of example progr
20. valid IOCTL Interface int rc struct DM6420HR_IO8 io_request Write to Timer Counter Control Register at I O base address 22 a io_request reg r_TIMER_CTRL_6420 Operate on timer counter 2 io_request value DM6420HR_CLK2 amp 0x3 lt lt 6 Put timer counter into Mode 2 rate generator mode a0 i0_request value I DM6420HR_CLK_MODE2 amp 0x7 lt lt 1 po DM6A20 Driver for Linux Set timer counter value to be accessed least significant byte first then most significant byte 10_request value 0x30 rc ioctl descriptor DM6420HR_IOCTL_OUTB amp io_request CloseBoard6420 int CloseBoard6420 int descriptor Description Close a DM6420 device file opened previously with OpenBoard6420 Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure Please see the close 2 or ioctl 2 man page for information on possible values errno may have in this case IOCTL Interface This function makes use of several ioctl requests ConfigDINClock6420 int ConfigDINClock6420 int descriptor enum DM6420HR_DI_FIFO_CLK DIN_Clock Description Set the source for a board s digital input FIFO clock Parameters descriptor File descriptor from OpenBoard6420 call DIN_Clock Source of digital input FIFO clock Valid values are DM6420HR_DI_FIFO_CLK_USER_TCO DM6420HR_DI_FIFO_CLK_USER_TC1 DM6420HR_DI_FIF
21. write access EINVAL callback is NULL EINVAL IRQChannel is not valid ENOMEM Library callback descriptor memory could not be allocated Please see the sigaction 2 man page the sigprocmask 2 man page or the ioctl 2 man page for information on other possible values errno may have in this case IOCTL Interface This function makes use of several ioctl requests InstalIDMA6420 int InstalIDMA6420 int descriptor enum DM6420HR_DMA DMAChannel Description Configure the specified DMA circuit on a board to be able to perform DMA DM6420 Driver for Linux 50 Parameters descriptor File descriptor from OpenBoard6420 call DMAChannel DMA circuit to configure Valid values are DM6420HR_DMA1 and DM6420HR_DMA2 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL DMAChannel is not valid EINVAL No DMA channel was ever allocated to DMAChannel ENOMEM DMA buffer memory allocation failed IOCTL Interface int rc struct DM6420HR_DI io_request Target of operation is second DMA circuit mh i0_request dma DM6420HR_DMA2 Enable DMA on the circuit 10_request action 1 rc ioctl descriptor DM6420HR_IOCTL_DMA_INSTALL amp io_request IsAboutTrigger6420 int IsAboutTrigger6420 int descriptor int ad_about_trigger_p Description Determine whether or not a board s A D about trigger has
22. 4 IOCTL Interface This function makes use of several ioctl requests LoadDINConfigRegister6420 int LoadDINConfigRegister6420 int descriptor u_int16_t value Description Load a 16 bit value into a board s Digital Input FIFO Configuration Register Parameters descriptor File descriptor from OpenBoard6420 call Value Value to write into register Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_IO16 io_request Write to Digital Input FIFO Configuration Register at base I O address 10 10_request reg r_DIN_CONFIG_6420 Set digital input FIFO clock source to output of user timer counter 1 io_request value 0x0001 DM6420 Driver for Linux 70 Enable digital input FIFO clock i io_request value l 1 lt lt 3 rc ioctl descriptor DM6420HR_IOCTL_OUTW amp io_request LoadIRQRegister6420 int LoadIRQRegister6420 int descriptor u_int16_t value Description Load a 16 bit value into a board s Interrupt Register Parameters descriptor File descriptor from OpenBoard6420 call Value Value to load into Interrupt Register Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_IO16 io_
23. 6420HR_DI io_request Operate on board s first DMA circuit i0_request dma DM6420HR_DMAI DMA can no longer be performed on the circuit 2i io_request action 0 rc ioctl descriptor DM6420HR_IOCTL_DMA_INSTALL amp io_request DINClockEnable6420 int DINClockEnable6420 int descriptor int Enable Description Enable or disable a board s digital input FIFO clock Parameters descriptor File descriptor from OpenBoard6420 call Enable Indicates whether or not to enable the digital input FIFO clock A value of 0 means disable the clock A nonzero value means enable the clock DM6420 Driver for Linux 22 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Digital Input FIFO Configuration Register at base I O address 10 io_request reg r_DIN_CONFIG_6420 Only change bit 3 in Configuration Register 10_request mask OxFFF7 Disable digital input FIFO clock i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request DIOClearChip6420 int DIOClearChip6420 int descriptor Description Clear a board s digital I O chip Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descr
24. Address where timer contents should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access EACCES descriptor refers to a file that is open but not for write access EINVAL Timer is not valid EINVAL Clock is not valid IOCTL Interface This function makes use of several ioctl requests M9 DM6A20 Driver for Linux RemoveIRQHandler6420 int RemoveIRQHandler6420 int descriptor enum DM6420HR_INT IRQChannel Description Uninstall the function which was previously registered as an interrupt callback by InstallCallbackIRQHandler6420 Parameters descriptor File descriptor from OpenBoard6420 call IRQChannel Board interrupt circuit that signal should be detached from Valid values are DM6420HR_INT1 and DM6420HR_INT2 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL IRQChannel is not valid EINVAL No IRQ was ever allocated to IRQChannel IOCTL Interface This function makes use of a single ioctl call However in addition to this ioctl call several other system calls are used to reset process signal handling state a description is beyond the scope of this document ResetChannelGainTable6420 int ResetChannelGainTable6420 int descriptor Description Reset a board s channel gain table starting point to the begi
25. DM6420 Driver for Linux User s Manual Version 2 01 xx ILUO RTD Embedded Technologies Inc Real Time Devices Accessing the Analog World SWM 640010014 rev C ISO9001 and AS9100 Certified RTD Embedded Technologies INC 103 Innovation Blvd State College PA 16803 0906 Phone 1 814 234 8087 FAX 1 814 234 5218 E mail sales rtd com techsupport rtd com web site http www rtd com DM6420 Driver for Linux st lt CSsti lt C i Revision History 04 20 2004 Revision A issued Documented for ISO9000 07 14 2005 Revision B issued Removed duplicate word in Using the API Functions section 4 11 2008 Revision C issued Released new version of the driver that supports 2 6 kernels Updated the driver revision number and documented changes related to the 2 6 kernel Added dm6420 dual dma data viewer example program DM6420 Driver for Linux Published by RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 Copyright 2005 by RTD Embedded Technologies Inc All rights reserved Printed in U S A The RTD Logo is a registered trademark of RTD Embedded Technologies cpuModule and dataModule are trademarks of RTD Embedded Technologies PS 2 PC XT PC AT and IBM are trademarks of International Business Machines Inc MS DOS Windows Windows 98 Windows NT Windows 2000 and Windows XP are trademarks of Microsoft Corp PC 104 is a registered trademark
26. DataMarker6420 int descriptor u_int8_t data_marker_p Description Read the 3 bit data marker from a board s analog to digital FIFO NOTE This function discards A D sample data from the A D FIFO data Calling ReadADDataMarker6420 and ReadADData6420 separately with the intention of getting data from a single sample will likely result in data being returned from two distinct samples Parameters descriptor File descriptor from OpenBoard6420 call Data_marker_p Address where data marker should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access DM6420 Driver for Linux 74 IOCTL Interface int rc struct DM6420HR_IO16 io_request u_int8_t data_marker Read from A D Data FIFO Register at base I O address 4 a io_request reg r_AD_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the A D data i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 data_marker u_int8_t io_request value amp 0x0007 ReadADDataWithMarker6420 int ReadADDataWithMarker6420 int descriptor int16_t ad_fifo_p Description Read the entire 16 bit contents of a board s analog to digital FIFO The most significant bit is the sign bit The next 12 bits are the co
27. Digital IRQ Strobe Status Register at base I O address 30 i0_request reg r DIO_STATUS_6420 326420 Driver for Linux Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request if re 1 If bit 5 is cleared in Status Register Then 8 MHz system clock in use Else User Timer Counter in use if io_request value amp 0x20 0 fprintf stdout 8 MHz system clock driving digital I O sampling n else fprintf stdout User Timer Counter driving digital I O sampling n DIOLoadCompare6420 int DIOLoadCompare6420 int descriptor u_int8_t Compare Description Load the Compare Register for a board s digital I O port 0 Parameters descriptor File descriptor from OpenBoard6420 call Compare The bit pattern to be matched Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface This function makes use of several ioctl requests DM6420 Driver for Linux DIOLoadMask6420 int DIOLoadMask6420 int descriptor u_int8_t Mask Description Load the Mask Register for a board s digital I O port 0 Parameters descriptor File descriptor from OpenBoard6420 call
28. Indicates whether or not A D conversion cycles repeat Valid values are DM6420HR_REPEAT_SINGLE and DM6420HR_REPEAT_REPEAT Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Repeat is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Trigger Mode Register at base I O address 6 io_request reg r_TRIGGER_6420 Only change bit 13 in register 10_request mask OxDFFF DM6420 Driver for Linux 96 Enable trigger repeat i io_request value 1 lt lt 13 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request SetUserClock6420 int SetUserClock6420 int descriptor enum DM6420HR_CLK Timer double InputRate double OutputRate double actual_p Description Set up a board s user clock Parameters descriptor File descriptor from OpenBoard6420 call Timer Indicates which counter to use Valid values are DM6420HR_CLKO DM6420HR_CLK1 and DM6420HR_CLK2 InputRate Input frequency to specified counter OutputRate Desired output rate from specified counter Actual_p Address where the actual programmed frequency should be stored If this function fails the actual frequency is not updated Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Timer is n
29. MA is finished a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 DM6420 Driver for Linux 64 i0_request reg r_ STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 Tf bit 5 is cleared in Status Register then first DMA is done If bit 5 is set then first DMA is not done if io_request value amp 0x0020 0 fprintf stdout First DMA done n IsPacerClockOn6420 int IsPacerClockOn6420 int descriptor int ad_pacer_clock_on_p Description Determine whether or not a board s A D pacer clock gate is on Parameters descriptor File descriptor from OpenBoard6420 call Ad_pacer_clock_on_p Address where A D pacer clock flag should be stored If A D pacer clock gate is on a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for
30. Mask The bit mask to be loaded Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface This function makes use of several ioctl requests DIORead6420 int DIORead6420 int descriptor enum DM6420HR_DIO Port u_int8_t digital_data_p Description Read 8 bits of data from board s specified digital I O port Parameters descriptor File descriptor from OpenBoard6420 call Port Indicates which digital I O port to read Valid values are DM6420HR_DIOO and DM6420HR_DIO1 Digital_data_p Address where data read should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access EINVAL Port is not valid 3B 00 DM6A20 Driver for Linux IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from Digital I O Port 1 Register at base I O address 26 i0_request reg r_ DIO_PORT_1_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request DIOReadCompareRegister6420 int DIOReadCompareRegister6420 int descriptor u_int8_t register_value_p Description Read the contents of a board s digital I O Compare Reg
31. O_CLK_AD_WRITE_FIFO DM6420HR_DI_FIFO_CLK_EXTERNAL_ PACER and DM6420HR_DI_FIFO_CLK_EXTERNAL_ TRIG DM6420 Driver for Linux 20 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL DIN_Clock is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Digital Input FIFO Configuration Register at base I O address 10 io_request reg r_DIN_CONFIG_6420 Only change bits 0 through 2 in Configuration Register io_request mask OxFFF8 Set source for digital input FIFO clock to the output of User Timer Counter 0 i0_request value DM6420HR_DI_FIFO_CLK_USER_TCO0 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request DelInstalIDMA6420 int DeInstalIDMA6420 int descriptor enum DM6420HR_DMA DMAChannel Description Configure the specified DMA circuit on a board so that DMA can no longer be performed on it Parameters descriptor File descriptor from OpenBoard6420 call DMAChannel DMA circuit to configure Valid values are DM6420HR_DMA1 and DM6420HR_DMA2 amo 6420 Driver for Linux Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL DMAChannel is not valid EINVAL No DMA channel was ever allocated to DMAChannel IOCTL Interface int rc struct DM
32. OpenBoard6420 call ADEntries Number of entries in A D table ADTable_p Address of memory containing A D table to send to board Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL ADFntries is 0 EINVAL ADEntries is greater than 1024 EINVAL An entry in the table pointed to by ADTable_p has an invalid Channel Gain ADRange or Se_Diff member variable value IOCTL Interface This function makes use of several ioctl requests LoadControlRegister6420 int LoadControlRegister6420 int descriptor u_int16_t value Description Load a value into a board s Control Register Parameters descriptor File descriptor from OpenBoard6420 call Value Data to write into Control Register M6420 Driver for Linux Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_IO16 io_request Write to Control Register at base I O address 2 io_request reg r CONTROL_6420 Set first DMA circuit to use DMA channel 5 i0_request value 1 lt lt 12 Set second DMA circuit to use DMA channel 7 io_request value l 3 lt lt 14 rc ioctl descriptor DM6420HR_IOCTL_OUTW amp io_request LoadDAC6420 int LoadDAC6420 int descriptor enum DM6420HR_DAC dac u
33. Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from the Digital IRQ Strobe Status Register at base I O address 30 io_request reg r DIO_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request if re 1 If bit 2 is set in Status Register Then Port 1 is output Else Port 1 is input 9 DM6A20 Driver for Linux if io_request value amp 0x04 fprintf stdout Port 1 set to output n else fprintf stdout Port 1 set to input n DIOIsChipStrobe6420 int DIOIsChipStrobe6420 int descriptor int strobe_occurred_p Description Determine whether or not data has been strobed into digital I O port 0 Parameters descriptor File descriptor from OpenBoard6420 call Strobe_occurred_p Address where strobe event flag should be stored If data was strobed into port 0 a nonzero value will be stored here Otherwise O will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc stru
34. TL_MOUTW amp io_request SetBurstClock6420 int SetBurstClock6420 int descriptor double BurstRate double actual_p Description Set a board s burst clock rate Parameters descriptor File descriptor from OpenBoard6420 call BurstRate Burst clock rate desired Actual_p Address where the actual programmed frequency should be stored If this function fails the actual frequency is not updated Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface This function makes use of several ioctl requests SetBurstTrigger6420 int SetBurstTrigger6420 int descriptor enum DM6420HR_BURST_TRIG Burst_Trigger Description Select a board s burst mode trigger DM6420 Driver for Linux 82 Parameters descriptor File descriptor from OpenBoard6420 call Burst_Trigger What triggers a burst Valid values are DM6420HR_BURST_TRIG_SOFTWARE DM6420HR_BURST_TRIG_PACER DM6420HR_BURST_TRIG_EXTERNAL and DM6420HR_BURST_TRIG_DIGITAL Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Burst_Trigger is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Trigger Mode Register at base I O address 6 io_request reg r_TRIGGER_6420 Only change bits 10 and 11 in Trigg
35. Trigger Mode Register i0_request mask OxFFFC Pacer clock controls A D conversion 10_request value 0x0001 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request SetIRQOSource6420 int SetIRQOSource6420 int descriptor enum DM6420HR_INTSRC IRQSource Description Select the interrupt source of the first interrupt circuit on a board Parameters descriptor File descriptor from OpenBoard6420 call DM6420 Driver for Linux 86 IRQSource Source of interrupt on first circuit Valid values are IRQS_AD_SAMPLE_CNT_6420 IRQS_AD_START_CONVERT_6420 IRQS_AD_END_CONVERT_6420 IRQS_AD_WRITE_FIFO_6420 IRQS_AD_FIFO_HALF_6420 IRQS_AD_DMA_DONE_ 6420 IRQS_RESET_GAIN_TABLE_6420 IRQS_PAUSE_GAIN_TABLE_6420 IRQS_EXT_PACER_CLOCK_ 6420 IRQS_EXT_TRIGGER_6420 IRQS_DIGITAL_6420 IRQS_TC_COUNTERO_6420 IRQS_TC_COUNTERO_INVERTED_6420 IRQS_TC_COUNTER1_6420 IRQS_DIO_FIFO_HALF_6420 and IRQS_DIO_WRITE_FIFO_ 6420 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL IRQSource is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Interrupt Register at base I O address 8 i0_request reg r_IRQ_ 6420 Only change bits 0 through 4 in register 10_request mask OxFFEO Set interrupt source to be A D FIFO half full
36. _int16_t Data Description Load a 12 bit binary value into one of the digital to analog converters on a board Parameters descriptor File descriptor from OpenBoard6420 call Dac D A converter to load Valid values are DM6420HR_DAC1 and DM6420HR_DAC2 Data Value to write to converter DM6420 Driver for Linux Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL dac is not valid IOCTL Interface int rc struct DM6420HR_IO16 io_request Write to DAC1 Output Register at base I O address 12 io_request reg r DAC1_6420 Write 1984 0x07C0 in two s complement to D A converter 10_request value 0x07C0 rc ioctl descriptor DM6420HR_IOCTL_OUTW amp io_request LoadDigitalTable6420 int LoadDigitalTable6420 int descriptor u_int16_t entries u_int8_t table_p Description Load a board s digital table with the given number of entries Parameters descriptor File descriptor from OpenBoard6420 call Entries Number of entries in digital table Table_p Address of memory containing digital table to send to board This memory is an array of unsigned bytes Return Value 0 Success Oo M6420 Driver for Linux 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL entries is 0 EINVAL entries is greater than 102
37. ams there are targets in Makefile to do so For example the command make dm6420 auto burst will compile and link the source file dm6420 auto burst cc and the command make dm6420 stream will compile and link the source file dm6420 stream cc The GNU C compiler gcc is used to compile the example program code 7 DM6420 Driver for Linux Using the API Functions DM6420 hardware and the associated driver functionality can be accessed through the library API Application Programming Interface functions Applications wishing to use library functions must include the include dm6420lib h header file and be statically linked with the lib librtd dm6420 a library file The following function reference provides for each library routine a prototype description explanation of parameters and return value or error code By looking at a function s entry you should gain an idea of 1 why it would be used 2 what it does 3 what information is passed into it 4 what information it passes back 5 how to interpret error conditions that may arise and 6 the ioctlQ system call interface if the function makes use of a single ioctl call Note that errno codes other than the ones indicated in the following pages may be set by the library functions Unless otherwise noted in the description of a function s return value please see the ioctl 2 man page for more information DM6420 Driver for Linux 8 Function Reference DM6420 Driver for L
38. atus flag whereas a subsequent write to this register will clear the digital I O chip ch i0_request value DM6420HR_REG_CLEAR rc ioctl descriptor DM6420HR_IOCTL_MOUTB amp io_request DIOSetPortODirection6420 int DIOSetPortODirection6420 int descriptor u_int8_t Direction Description Set the digital I O port 0 bit direction input or output on a board DM6420 Driver for Linux 38 Parameters descriptor Direction Return Value 0 1 EACCES IOCTL Interface File descriptor from OpenBoard6420 call Bit mask indicating bit direction for port 0 bits A 1 in the mask means set that bit to output A 0 in the mask means set that bit to input Success Failure with errno set as follows descriptor refers to a file that is open but not for write access This function makes use of several ioctl requests DIOSetPort1 Direction6420 int DIOSetPort1Direction6420 int descriptor int Direction Description Set the digital I O port 1 bit direction input or output on a board Parameters descriptor Direction Return Value 0 1 EACCES IOCTL Interface int rc File descriptor from OpenBoard6420 call Flag indicating bit direction A value of 0 means set port 1 bits to input A nonzero value means set port bits to output Success Failure with errno set as follows descriptor refers to a file that is open but not for write access struct DM6420HR_MIO8 io_
39. ct DM6420HR_IO8 io_request Read from the Digital IRQ Strobe Status Register at base I O address 30 i io_request reg r_DIO_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request if rc 1 DM6420 Driver for Linux 30 If bit 7 is set in Status Register Then Data was strobed into port 0 Else No data strobed if io_request value amp 0x80 fprintf stdout Data strobed into digital I O port 0 n else fprintf stdout No data strobed into digital I O port 0 n DIOIsChipSystemClock6420 int DIOIsChipSystemClock6420 int descriptor int system_clock_p Description Determine whether or not the 8 MHz system clock is driving digital I O sampling Parameters descriptor File descriptor from OpenBoard6420 call System_clock_p Address where system clock flag should be stored If the 8 MHz system clock is driving digital sampling a nonzero value will be stored here Otherwise O will be stored here meaning that the User Timer Counter is driving sampling Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from the
40. cted and 4 if a function can accept multiple valid inputs it succeeds on all combinations of such inputs dm6420 throughput Allows one to see how the driver works when a board is converting A D data at a particular throughput rate and converted data is being read using a specified method Data can be retrieved as follows 1 reading one sample at a time 2 using streaming input 3 using single channel DMA and 4 using dual channel DMA In all cases interrupts are used to signal availability of data Every five seconds the program prints status information dm6420 timers Demonstrates how to program the 8254 programmable interval timers dm6420 user timer Demonstrates how to set up the User Timer to generate interrupts at a specified rate poll the appropriate interrupt counter and perform an A D conversion when the counter changes w DM6A20 Driver for Linux Limited Warranty RTD Embedded Technologies Inc warrants the hardware and software products it manufactures and produces to be free from defects in materials and workmanship for one year following the date of shipment from RTD Embedded Technologies INC This warranty is limited to the original purchaser of product and is not transferable During the one year warranty period RTD Embedded Technologies will repair or replace at its option any defective products or parts at no additional charge provided that the product is returned shipping prepaid to RTD Embedded Tec
41. curring a nonzero value will be stored here Otherwise O will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 ai io_request reg r_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 Tf bit 3 is cleared in Status Register then A D converter is converting Tf bit 3 is set then A D converter is not converting rf 3 00026420 Driver for Linux if io_request value amp 0x0008 0 fprintf stdout A D converter is still converting n IsADDMADone6420 int IADDMADone6420 int descriptor int ad_dma_done_p Description Determine whether or not a board s A D DMA transfer is complete Parameters descriptor File descriptor from OpenBoard6420 call Ad_dma_done_p Address where A D DMA done flag should be stored If A D DMA is finished a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for
42. e Otherwise O will be stored here meaning digital interrupts are in match mode Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from the Digital IRQ Strobe Status Register at base I O address 30 io_request reg r DIO_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read a 10_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request if rc 1 If bit 3 is cleared in Status Register Then Interrupt mode is event Else Interrupt mode is match if io_request value amp 0x08 0 fprintf stdout Digital I O interrupts in event mode n else fprintf stdout Digital I O interrupts in match mode n DM6420 Driver for Linux 28 DIOIsChipPort1 Output6420 int DIOIsChipPort Output6420 int descriptor int port _output_p Description Determine whether or not a board s digital port 1 is set to output Parameters descriptor File descriptor from OpenBoard6420 call Port1_output_p Address where port 1 output flag should be stored If port 1 is set to output a nonzero value will be stored here Otherwise 0 will be stored here meaning port is set to input
43. e and software entities are involved in device access 2 shows which units communicate with each other and 3 illustrates the methods used to transfer data and control information Application Application Application C Function Calls C Function Calls C Function Calls Library ioctl System Calls User Space Kernel Space Driver Software I O Space Accesses Hardware Electrical Signals Hardware 5 DM6420 Driver for Linux Installation Instructions Extracting the Software All software comes packaged in a gzip d tar file named dm6420_Linux_v2 01 xx tar gz _ First decide where you would like to place the software and make a copy of the tar file in this directory by issuing the command cp lt path to tar file gt dm6420_Linux_v2 01 xx tar gz lt installation path gt substituting the appropriate paths for lt path to tar file gt and lt installation path gt Next change your current directory to where you made a copy of the tar file by issuing the command cd lt installation path gt Once you are in this directory extract the software by issuing the command tar xvzf dm6420_Linux_v2 01 xx tar gz this will create a directory dm6420_Linux_v2 01 xx tar gz which contains all the files that are part of the software package Contents of Installation Directory Once the tar file is extracted you should see the following files and directories within dm6420_Linux_v2 01 xx driver examples i
44. ed If the digital FIFO is empty a nonzero value will be stored here Otherwise O will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 io_request reg r_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents oh i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 Tf bit 10 is set in Status Register then digital input FIFO is not empty Tf bit 10 is cleared then digital input FIFO is empty if io_request value amp 0x0400 fprintf stdout Digital input FIFO is not empty n 626420 Driver for Linux IsDINFIFOFull6420 int ISDINFIFOFull6420 int descriptor int digital_fifo_full_p Description Determine whether or not a board s digital input FIFO is full Parameters descriptor File descriptor from OpenBoard6420 call Digital_fifo_full_p Address where digital FIFO full flag should be stored If the digital FIFO is full a nonzero value will be stored here Otherwise O will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor ref
45. er Mode Register io_request mask OxF3FF Bursts triggered by external trigger io_request value 1 lt lt 11 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request 83 DM6420 Driver for Linux SetChannelGain6420 int SetChannelGain6420 int descriptor enum DM6420HR_AIN Channel enum DM6420HR_GAIN Gain enum DM6420HR_RANGE Range enum DM6420HR_SE Se_Diff Description Load a board s channel gain latch Parameters descriptor File descriptor from OpenBoard6420 call Channel A D channel Valid values are DM6420HR_AIN1 M6420HR_AIN2 DM6420HR_AIN3 DM6420HR_AIN4 M6420HR_AINS DM6420HR_AIN6 DM6420HR_AIN7 M6420HR_AIN8 DM6420HR_AIN9 DM6420HR_AIN10 M6420HR_AIN11 DM6420HR_AIN12 DM6420HR_AIN13 M6420HR_AIN14 DM6420HR_AIN15 and DM6420HR_AIN16 JFJ Gain A D gain Valid values are DM6420HR_GAINx1 DM6420HR_GAINx2 DM6420HR_GAINx4 and DM6420HR_GAINX8 Range A D input voltage range and polarity Valid values are DM6420HR_RANGE_SIGNEDS DM6420HR_RANGE_SIGNED10 and DM6420HR_RANGE_ UNSIGNED 10 Se_Diff Select single ended or differential mode Valid values are DM6420HR_SE_SE and DM6420HR_SE_DIFF Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Channel is not valid EINVAL Gain is not valid EINVAL Range is not valid EINVAL Se_Diff is not valid DM6420 Driver for
46. ers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 a 10_request reg r_ STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 Tf bit 12 is cleared in Status Register then digital input FIFO is full x Tf bit 12 is set then digital input FIFO is not full ay DM6420 Driver for Linux 62 if io_request value amp 0x1000 0 fprintf stdout Digital input FIFO is full n IsDINFIFOHalf6420 int ISDINFIFOHaIf6420 int descriptor int digital_fifo_half_full_p Description Determine whether or not a board s digital input FIFO is half full Parameters descriptor File descriptor from OpenBoard6420 call Digital_fifo_half_full_p Address where digital FIFO half full flag should be stored If the digital FIFO is half full a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address
47. ferred are 16 bit signed converted A D values Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL DMAChannel is not valid EINVAL No DMA channel was ever allocated to DMAChannel EINVAL No DMA buffer was ever allocated to DMAChannel EINVAL TransferBytes is odd EINVAL TransferBytes is greater than the DMA buffer size IOCTL Interface int rc struct DM6420HR_DST io_request Target of operation is first DMA circuit io_request dma DM6420HR_DMA1 DMA transfer size is 4096 bytes 2048 words io_request length 4096 rc ioctl descriptor DM6420HR_IOCTL_DMA_START amp io_request StopDMA6420 int StopDMA6420 int descriptor enum DM6420HR_DMA DMAChannel Description Stop DMA on a board s specified DMA circuit 9 DM6420 Driver for Linux Parameters descriptor DMAChannel Return Value 0 1 EACCES EINVAL EINVAL IOCTL Interface int rc File descriptor from OpenBoard6420 call DMA circuit to operate on Valid values are DM6420HR_DMAI1 and DM6420HR_DMA2 Success Failure with errno set as follows descriptor refers to a file that is open but not for write access DMAChannel is not valid No DMA channel was ever allocated to DMAChannel Halt DMA on second DMA circuit re ioctl descriptor DM6420HR_IOCTL_DMA_STOP DM6420HR_DMA2 DM6420 Driver for L
48. he sample clock source for a board s digital I O chip 3 OC lt lt O64 0 Driver for Linux Parameters descriptor File descriptor from OpenBoard6420 call Clock Indicates the clock source Valid values are DM6420HR_CLOCK_TC and DM6420HR_USER_TC Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Clock is not valid IOCTL Interface int rc struct DM6420HR_MIO8 io_request Write to Digital Mode Register at base I O address 30 i0_request reg r DIO_MODE_6420 Only change bit 5 in Mode Register i0_request mask OxDF Set digital I O sample clock source to User Timer Counter 1 io_request value DM6420HR_USER_TC lt lt 5 rc ioctl descriptor DM6420HR_IOCTL_MOUTB amp io_request DIOSelectIrqMode6420 int DIOSelectIrqMode6420 int descriptor enum DM6420HR_DIO_IRQ IrqMode Description Set the advanced digital interrupt mode for a board s digital I O chip port 0 DM6420 Driver for Linux 36 Parameters descriptor File descriptor from OpenBoard6420 call IrqMode Indicates the digital interrupt mode Valid values are DM6420HR_DIO_IRQ_EVENT and DM6420HR_DIO_IRQ_ MATCH Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL IrqMode is not valid IOCTL Interface int rc st
49. hnologies All replaced parts and products become the property of RTD Embedded Technologies Before returning any product for repair customers are required to contact the factory for an RMA number THIS LIMITED WARRANTY DOES NOT EXTEND TO ANY PRODUCTS WHICH HAVE BEEN DAMAGED AS A RESULT OF ACCIDENT MISUSE ABUSE such as use of incorrect input voltages improper or insufficient ventilation failure to follow the operating instructions that are provided by RTD Embedded Technologies acts of God or other contingencies beyond the control of RTD Embedded Technologies OR AS A RESULT OF SERVICE OR MODIFICATION BY ANYONE OTHER THAN RTD Embedded Technologies EXCEPT AS EXPRESSLY SET FORTH ABOVE NO OTHER WARRANTIES ARE EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FIT NESS FOR A PARTICULAR PURPOSE AND RTD Embedded Technologies EXPRESSLY DISCLAIMS ALL WARRANTIES NOT STATED HEREIN ALL IMPLIED WARRANTIES INCLUDING IMPLIED WARRANTIES FOR MECHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE LIMITED TO THE DURATION OF THIS WARRANTY IN THE EVENT THE PRODUCT IS NOT FREE FROM DEFECTS AS WARRANTED ABOVE THE PURCHASER S SOLE REMEDY SHALL BE REPAIR OR REPLACEMENT AS PROVIDED ABOVE UNDER NO CIRCUMSTANCES WILL RTD Embedded Technologies BE LIABLE TO THE PURCHASER OR ANY USER FOR ANY DAMAGES INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES EXPENSES LOST PROFITS LOST SAVINGS OR OTHER DAMAGES ARISING
50. integer returned is the file descriptor from open system call 1 Failure Please see the open 2 man page for information on possible values errno may have in this case IOCTL Interface None ReadADData6420 int ReadADData6420 int descriptor intl6_t ad_data_p Description Read the 12 bit A D sample from a board s analog to digital FIFO NOTE This function discards marker data from the A D FIFO data Calling ReadADData6420 and ReadADDataMarker6420 separately with the intention of getting data from a single sample will likely result in data being returned from two distinct samples Parameters descriptor File descriptor from OpenBoard6420 call Ad_data_p Address where A D sample data read should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access BM 6420 Driver for Linux IOCTL Interface int rc int16_t ad_data struct DM6420HR_IO16 io_request Read from A D Data FIFO Register at base I O address 4 10_request reg r_AD_6420 Any value works here because it is ignored making this request However on return from joctl the member variable value contains the A D data oh i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 ad_data int16_t io_request value gt gt 3 ReadADDataMarker6420 int ReadAD
51. inux 100 Example Programs Reference Name Remarks dm6420 auto burst Demonstrates how to use the pacer clock burst clock sample counter and channel gain table to scan groups of channels multiple times multi scan sampling dm6420 dac dm6420 digital interrupt 0 for input and port for output dm6420 dma dm6420 dual dma dm6420 dual dma data viewer Demonstrates how to read the data from the dual_dma dat file generated by the dm6420 dual dma example program multiple channels using the channel gain table dm6420 sample counter software trigger dm6420 speed test Demonstrates three different IRQ handling and data read methods 1 using a callback routine invoked via the driver interrupt handler sending a signal to the process data is read using streaming input 2 polling the IRQ counter for an interrupt circuit data is read one sample at a time and 3 polling the IRQ counter for an interrupt circuit data is read using streaming input dm6420 stream Demonstrates using streaming input to read blocks of data from the digital input FIFO dm6420 test lib errors Test program to validate library error checking This program exercises the error checking code added to the library All exported functions are verified The following types of tests are performed 1 a function fails when expected 2 if a function fails as expected errno is set as expected depending upon the cause of failure 3 a function succeeds when expe
52. inux API Function Groups Analog to Digital Conversion ChannelGainDataStore6420 ClearADFIFO6420 ClearChannelGainTable6420 EnableTables6420 GetAutoincData6420 IsAboutTrigger6420 IsADConverting6420 IsADFIFOEmpty6420 IsADFIFOFull6420 IsADHalted6420 LoadADSampleCounter6420 LoadADTable6420 LoadDigitalTable6420 LoadTriggerRegister6420 ReadADData6420 ReadADDataMarker6420 ReadADDataWithMarker6420 ReadChannelGainDataStore6420 ResetChannelGainTable6420 SetBurstTrigger6420 SetChannelGain6420 SetConversionSelect6420 SetPauseEnable6420 SetStartTrigger6420 SetStopTrigger6420 SetTriggerPolarity6420 SetTriggerRepeat6420 StartConversion6420 Digital to Analog Conversion LoadDAC6420 DM6420 Driver for Linux 10 Digital I O ClearDINFIFO6420 ConfigDINClock6420 DIOClearChip6420 DINClockEnable6420 DIOClearIrq6420 DIOEnableIrq6420 DIOIsChipIrq6420 DIOIsChipIRQEnabled6420 DIOIsChipIRQEventMode6420 DIOIsChipPort1 Output6420 DIOIsChipStrobe6420 DIOIsChipSystemClock6420 DIOLoadCompare6420 DIOLoadMask6420 DIORead6420 DIOReadCompareRegister6420 DIOReadStatus6420 DIOSelectClock6420 DIOSelectIrqMode6420 DIOSelectRegister6420 DIOSetPortODirection6420 DIOSetPort Direction6420 DIOWrite6420 IsDigitalIRQ6420 IsDINFIFOEmpty6420 IsDINFIFOFull6420 IsDINFIFOHalf6420 LoadDINConfigRegister6420 ReadDINFIFO6420 Direct Memory Access DMA Data Transfer ClearADDMADone6420 DelInstallIDMA6420 GetDmaData6420 InstalIDMA6420 IsADDMADone6420
53. ioctl the member variable value contains the register contents t7 io_request value 0 BSS 26420 Driver for Linux rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 Tf bit 0 is cleared in Status Register then A D FIFO is empty Tf bit 0 is set then A D FIFO is not empty if io_request value amp 0x0001 0 fprintf stdout A D FIFO empty n IsADFIFOFull6420 int IE ADFIFOFull6420 int descriptor int ad_fifo_full_p Description Determine whether or not a board s A D FIFO is full Parameters descriptor File descriptor from OpenBoard6420 call Ad_fifo_empty_p Address where FIFO full flag should be stored If the A D FIFO is full a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 10_request reg r_ STATUS_6420 DM6420 Driver for Linux 56 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents a i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 Tf bit 1 is set in Status Register the
54. iptor from OpenBoard6420 call IRQChannel Interrupt circuit to disable Valid values are DM6420HR_INT1 and DM6420HR_INT2 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL IRQChannel is not valid IOCTL Interface int rc struct DM6420HR_IE io_request Target of operation is second interrupt circuit A io_request intr DM6420HR_INT2 Disable the interrupt circuit 10_request action 0 rc ioctl descriptor DM6420HR_IOCTL_IRQ ENABLE amp io_request 41 DM6420 Driver for Linux DoneTimer6420 int DoneTimer6420 int descriptor Description Initialize a board s user timer counter counter 0 and counter 1 for high speed to ensure immediate load This function puts these two counters into mode 2 Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure Please see the descriptions of the ClockDivisor6420 ClockMode64200 and SelectTimerCounter6420 functions or the ioctl 2 man page for information on possible values errno may have in this case IOCTL Interface This function makes use of several ioctl requests EnableIRQ6420 int EnableIRQ6420 int descriptor enum DM6420HR_INT IRQChannel Description Enable the specified interrupt circuit on a board Parameters descriptor File descriptor from OpenBoard6420 call IRQChannel
55. iptor refers to a file that is open but not for write access 3B DM6420 Driver for Linux IOCTL Interface This function makes use of several ioctl requests DIOClearlrq6420 int DIOClearIrq6420 int descriptor Description Clear a board s digital I O IRQ status flag Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface This function makes use of several ioctl requests DIOEnableIrq6420 int DIOEnableIrq6420 int descriptor int Enable Description Enable or disable a board s digital interrupts Parameters descriptor File descriptor from OpenBoard6420 call Enable Flag indicating how digital interrupts should be set A value of 0 means disable digital interrupts A nonzero value means enable digital interrupts DM6420 Driver for Linux 24 Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_MIO8 io_request Write to Digital Mode Register at base I O address 30 io_request reg r_DIO_MODE_6420 Only change bit 4 in Mode Register 10_request mask OxEF Enable digital interrupts io_request value 1 lt lt 4 rc ioctl descriptor DM6420HR_IOCTL_MOUTB a
56. ister Parameters descriptor File descriptor from OpenBoard6420 call Register_value_p Address where register contents should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface This function makes use of several ioctl requests DM6420 Driver for Linux 34 DIOReadStatus6420 int DIOReadStatus6420 int descriptor u_int8_t status_p Description Read the contents of a board s Digital IRQ Strobe Status register Other library functions make use of this routine to perform their work Parameters descriptor File descriptor from OpenBoard6420 call Status_p Address where digital I O status register contents should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from Digital IRQ Strobe Status Register at base I O address 30 io_request reg r DIO_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request DIOSelectClock6420 int DIOSelectClock6420 int descriptor enum DM6420HR_CLK_SEL Clock Description Select t
57. le buffer being full n IsBurstClockOn6420 int IsBurstClockOn6420 int descriptor int ad_burst_clock_on_p Description Determine whether or not a board s A D burst clock gate is on Parameters descriptor File descriptor from OpenBoard6420 call Ad_burst_clock_on_p Address where A D burst clock flag should be stored If A D burst clock gate is on a nonzero value will be stored here Otherwise O will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access DM6420 Driver for Linux 58 IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 10_request reg r_ STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents ih i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 Tf bit 6 is set in Status Register then burst gate is on Tf bit 6 is cleared then burst gate is off if io_request value amp 0x0040 fprintf stdout Burst gate is on n IsDigitalIRQ6420 int IsDigitalIRQ6420 int descriptor int digital_interrupt_p Description Determine whether or not an advanced digital mode interrupt has occurred on a board
58. mp io_request DIOIsChipIrq6420 int DIOIsChipIrq6420 int descriptor int interrupt_generated_p Description Determine whether or not a board has generated a digital I O interrupt Parameters descriptor File descriptor from OpenBoard6420 call Interrupt_generated_p Address where interrupt generated flag should be stored If the board has generated a digital I O interrupt a nonzero value will be stored here Otherwise 0 will be stored here 32 tsts S 26420 Driver for Linux Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from the Digital IRQ Strobe Status Register at base I O address 30 ah i0_request reg r_ DIO_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request if re 1 Tf bit 6 is set in Status Register an interrupt occurred oF if io_request value amp 0x40 fprintf stdout Digital I O interrupt generated n DIOIsChipIRQEnabled6420 int DIOIsChipIRQEnabled6420 int descriptor int irq_enabled_p Description Determine whether or not digital interrupts are enabled for a board Parameters descrip
59. n A D FIFO is not full ok Tf bit 1 is cleared then A D FIFO is full if io_request value amp 0x0002 fprintf stdout A D FIFO not full n IsADHalted6420 int ISADHalted6420 int descriptor int ad_halted_p Description Determine whether or not a board s A D conversion has been stopped because the sample buffer is full Parameters descriptor File descriptor from OpenBoard6420 call Ad_halted_p Address where A D halted flag should be stored If A D conversion has been stopped a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request 726420 Driver for Linux Read from Status Register at base I O address 2 10_request reg r STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents 2 i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 Tf bit 2 is cleared in Status Register then A D conversion has not been stopped Tf bit 2 is set then A D conversion has been stopped t if io_request value amp 0x0004 0 fprintf stdout A D conversion not halted due to samp
60. nclude lib CHANGES TXT LICENSE TXT README TXT The file CHANGES TXT describes the changes made to the software for this release as well as for previous releases The file LICENSE TXT provides details about the RTD end user license agreement which must be agreed to and accepted before using this software The file README TXT contains a general overview of the software and contact information should you experience problems have questions or need information The directory driver contains the source code and Makefile for the drivers The directory examples holds the source code and Makefile for the example programs The directory include contains all header files used by the driver example programs library and your application programs Library source code and Makefile reside in the directory lib Building the Driver Driver source code uses files located in the kernel source tree Therefore you must have the full kernel source tree available in order to build the driver The kernel source tree consumes a lot of disk space on the order of 100 to 200 megabytes Because production systems rarely contain this much disk space you will probably use a development machine to compile the driver source code The development system which provides a full compilation environment must be running the exact same version of the kernel as your production machine s otherwise the kernel module may not load or may load improperly After the code is buil
61. nning of the table Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success DM6420 Driver for Linux 80 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_RESET_GAIN SelectTimerCounter6420 int SelectTimerCounter6420 int descriptor enum DM6420HR_CLK_SEL Select Description Select which timer counter on a board will be accessed when a subsequent operation is performed on the registers located at base I O address 16 through base I O address 22 Other library functions make use of this routine to perform their work Parameters descriptor File descriptor from OpenBoard6420 call Select Indicate which timer counter will be accessed Valid values are DM6420HR_CLOCK_TC and DM6420HR_USER_TC Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Select is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Control Register at base I O address 2 10_request reg r CONTROL_6420 Only change bits 5 and 6 in Control Register shots 26420 Driver for Linux 10_request mask OxFF9F Select User Timer Counter 10_request value 1 lt lt 5 rc ioctl descriptor DM6420HR_IOC
62. ns as defined in the hardware manual IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Trigger Mode Register at base I O address 6 a 10_request reg r_TRIGGER_6420 Only change bits 2 through 4 in register io_request mask OxFFE3 Start pacer clock when User Timer Counter 1 counts down to zero io_request value 0x3 lt lt 2 83 DM6A20 Driver for Linux rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request SetStopTrigger6420 int SetStopTrigger6420 int descriptor enum DM6420HR_STOP_TRIG Stop_Trigger Description Configure how a board s pacer clock is stopped during A D conversion Parameters descriptor File descriptor from OpenBoard6420 call Stop_Trigger What stops the pacer clock Valid values are M6420HR_STOP_TRIG_SOFTWARE M6420HR_STOP_TRIG_EXTERNAL M6420HR_STOP_TRIG_DIGITAL_INT M6420HR_STOP_TRIG_SAMPLE_ CNT M6420HR_STOP_TRIG_ABOUT_SOFTWARE M6420HR_STOP_TRIG_ABOUT_EXTERNAL M6420HR_STOP_TRIG_ABOUT_DIGITAL and M6420HR_STOP_TRIG_ABOUT_USER_TC1 gggggggg Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Stop_Trigger is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Trigger Mode Register at base I O address 6 io_request reg r_TRIGGER_6420 Only change bits 5 through 7 in register
63. nverted A D data The least significant 3 bits are the data marker Parameters descriptor File descriptor from OpenBoard6420 call Ad_fifo_p Address where A D FIFO contents should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access 53o DM6A20 Driver for Linux IOCTL Interface int rc int16_t ad_data struct DM6420HR_IO16 io_request u_int8_t data_marker Read from A D Data FIFO Register at base I O address 4 10_request reg r_AD_6420 Any value works here because it is ignored making this request However on return from joctl the member variable value contains the A D data i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if re 1 ad_data int16_t io_request value gt gt 3 data_marker u_int8_t io_request value amp 0x0007 ReadChannelGainDataStore6420 int ReadChannelGainDataStore6420 int descriptor u_intl6_t cgds_data_p Description Read a board s channel gain data word This function assumes the caller knows whether or not the channel gain data store has been enabled since there is no way to query the board for this status Parameters descriptor File descriptor from OpenBoard6420 call Cgds_data_p Address where data read should be stored Return Value 0 Success 1 Failure with errno set as f
64. occurred so 26420 Driver for Linux Parameters descriptor File descriptor from OpenBoard6420 call Ad_about_trigger_p Address where A D about trigger flag should be stored If A D about trigger has occurred a nonzero value will be stored here Otherwise 0 will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 io_request reg r_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents 10_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request if rc 1 Tf bit 8 is set in Status Register then about trigger has occurred Tf bit 8 is cleared then about trigger has not occurred if io_request value amp 0x0100 fprintf stdout About trigger occurred n DM6420 Driver for Linux 52 IsADConverting6420 int IsADConverting6420 int descriptor int ad_converting_p Description Determine whether or not a board s A D converter is converting Parameters descriptor File descriptor from OpenBoard6420 call Ad_converting_p Address where A D converting flag should be stored If A D conversion is oc
65. ollows EACCES descriptor refers to a file that is open but not for read access DM6420 Driver for Linux 76 IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from A D Data FIFO Register at base I O address 4 10_request reg r_AD_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the channel gain data il i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request ReadDINFIFO6420 int ReadDINFIFO6420 int descriptor u_int8_t digital_data_p Description Read 8 bits of data from the port 0 digital input FIFO Parameters descriptor File descriptor from OpenBoard6420 call Digital_data_p Address where data read should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from Digital Input FIFO Register at base I O address 10 T io_request reg r_DIN_FIFO_6420 Wo DM6A20 Driver for Linux Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the digital data i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request ReadStatus6420 int ReadStatus6420 int descript
66. or u_int16_t status_p Description Read a board s Status Register Other library functions make use of this routine to perform their work Parameters descriptor File descriptor from OpenBoard6420 call Status_p Address where status should be stored Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Status Register at base I O address 2 io_request reg r STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the register contents io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request DM6420 Driver for Linux 78 ReadTimerCounter6420 int ReadTimerCounter6420 int descriptor enum DM6420HR_CLK_SEL Timer enum DM6420HR_CLK Clock u_int16_t counter_value_p Description Read the 16 bit contents of the desired timer counter The read is done as two 8 bit reads least significant byte then most significant byte Parameters descriptor File descriptor from OpenBoard6420 call Timer Indicates which timer counter to use Valid values are DM6420HR_CLOCK_TC and DM6420HR_USER_TC Clock Indicates which counter to use Valid values are DM6420HR_CLKO DM6420HR_CLK1 and DM6420HR_CLK2 Counter_value_p
67. ot valid IOCTL Interface This function makes use of several ioctl requests 7 DM6420 Driver for Linux StartConversion6420 int StartConversion6420 int descriptor Description Issue a Start Convert software trigger command to a board Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO16 io_request Read from Start Convert Register at base I O address 6 10_request reg r START_CONVERSION_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the data read but in this case we re not interested in the value at all just the fact that the read was performed ap i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INW amp io_request StartDMA6420 int StartDMA6420 int descriptor enum DM6420HR_DMA DMAChannel size_t TransferBytes Description Start DMA on a board s specified DMA circuit Parameters descriptor File descriptor from OpenBoard6420 call DM6420 Driver for Linux 98 DMAChannel DMA circuit to operate on Valid values are DM6420HR_DMAI1 and DM6420HR_DMA2 TransferB ytes Number of bytes to transfer in a single DMA This value must be even because the entities trans
68. r write access IOCTL Interface int rc rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_BOARD ClearChannelGainTable6420 int ClearChannelGainTable6420 int descriptor Description Clear the contents of a board s channel gain table Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_CLEAR_GAIN BU 2M 6420 Driver for Linux ClearDINFIFO6420 int ClearDINFIFO6420 int descriptor Description Clear a board s digital input FIFO Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_DIO_ FIFO ClearIRQ06420 int ClearIRQ06420 int descriptor Description Clear the first interrupt circuit on a board Parameters descriptor File descriptor from OpenBoard6420 call Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc rc ioctl descriptor DM6420HR_IOCTL_CLEAR DM6420_CL_IRQ1 DM6420 Driver for Linux 16
69. rd6420 call Disable Flag to indicate whether the A D sample counter should stop the pacer clock A value of 0 means enable sample counter stop A nonzero value means disable sample counter stop Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Control Register at base I O address 2 io_request reg r CONTROL_6420 Only change bit 7 in register 10_request mask OxFF7F Disable A D sample counter stop 10_request value 1 lt lt 7 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request DM6420 Driver for Linux 92 SetStartTrigger6420 int SetStartTrigger6420 int descriptor enum DM6420HR_START_TRIG Start_Trigger Description Configure how a board s pacer clock is started during A D conversion Parameters descriptor File descriptor from OpenBoard6420 call Start_Trigger What starts the pacer clock Valid values are DM6420HR_START_TRIG_SOFTWARE DM6420HR_START_TRIG_EXTERNAL DM6420HR_START_TRIG_DIGITAL_INT DM6420HR_START_TRIG_USER_TC1 and DM6420HR_START_TRIG_GATE Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Start_Trigger is not valid EOPNOTSUPP Start_Trigger is one of the three reserved bit patter
70. request Write to Digital Mode Register at base I O address 30 a i0_request reg r DIO_MODE_6420 39 DM6420 Driver for Linux Only change bit 2 in Mode Register i0_request mask OxFB Set digital I O port 1 bit direction to output All port bits are set to this direction er 10_request value 1 lt lt 2 rc ioctl descriptor DM6420HR_IOCTL_MOUTB amp io_request DIOWrite6420 int DIOWrite6420 int descriptor enum DM6420HR_DIO Port u_int8_t Data Description Write data to a board s selected digital I O port Parameters descriptor Port Data Return Value 0 1 EACCES EINVAL IOCTL Interface int rc File descriptor from OpenBoard6420 call The port to write to Valid values are DM6420HR_DIOO and DM6420HR_DIO1 The data to write Success Failure with errno set as follows descriptor refers to a file that is open but not for write access Port is not valid struct DM6420HR_IO8 io_request Write to digital I O port 0 io_request reg r DIO_PORT_0_6420 DM6420 Driver for Linux 40 Write the value 0x44 68 decimal 10_request value 0x44 rc ioctl descriptor DM6420HR_IOCTL_OUTB amp io_request DisableIRQ6420 int DisableIRQ6420 int descriptor enum DM6420HR_INT IRQChannel Description Disable the specified interrupt circuit on a board Parameters descriptor File descr
71. request Write to Interrupt Register at base I O address 8 a io_request reg r IRQ 6420 Set source of interrupts on first circuit to be write to digital input FIFO i0_request value 0x000F Use IRQS for first interrupt circuit 10_request value l 1 lt lt 6 mo M6420 Driver for Linux rc ioctl descriptor DM6420HR_IOCTL_OUTW amp io_request LoadTriggerRegister6420 int LoadTriggerRegister6420 int descriptor u_int16_t value Description Load a 16 bit value into a board s Trigger Mode Register Parameters descriptor File descriptor from OpenBoard6420 call Value Value to write into Trigger Mode Register Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_IO16 io_request Write to Trigger Mode Register at base I O address 6 10_request reg r_TRIGGER_6420 Pacer Clock controls A D conversion i0_request value 0x0001 Start Pacer Clock when digital interrupt received a i0_request value I 1 lt lt 3 rc ioctl descriptor DM6420HR_IOCTL_OUTW amp io_request DM6420 Driver for Linux 72 OpenBoard6420 int OpenBoard6420 int DeviceNumber Description Open a DM6420 device file Parameters DeviceNumber Minor number of board device file Return Value gt 0 Success The
72. ruct DM6420HR_MIO8 io_request Write to Digital Mode Register at base I O address 30 io_request reg r_DIO_MODE_6420 Only change bit 3 in Mode Register io_request mask 0xF7 Set digital I O interrupt mode to Event Mode io_request value DM6420HR_DIO_IRQ_EVENT lt lt 3 rc ioctl descriptor DM6420HR_IOCTL_MOUTB amp io_request DIOSelectRegister6420 int DIOSelectRegister6420 int descriptor enum DM6420HR_REG_SEL Select Description Set the mode of a board s digital I O port 0 Direction Mask Compare Register located at base I O address 28 Other library functions make use of this routine to perform their work 3726420 Driver for Linux Parameters descriptor File descriptor from OpenBoard6420 call Select Which mode to configure Valid values are DM6420HR_REG_CLEAR DM6420HR_REG_DIR DM6420HR_REG_MASK and DM6420HR_REG_CMP Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Select is not valid IOCTL Interface int rc struct DM6420HR_MIO8 io_request Write to Digital Mode Register at base I O address 30 gji io_request reg r_DIO_MODE_6420 Only change bits 0 and 1 in Mode Register t io_request mask OxFC Put digital I O port 0 Direction Mask Compare Register into Clear Mode A subsequent read from this register will clear the digital IRQ st
73. set to receive the divisor least significant byte first then most significant byte Parameters descriptor Timer Divisor Return Value 0 1 EACCES EINVAL IOCTL Interface File descriptor from OpenBoard6420 call Indicates which counter to use Valid values are DM6420HR_CLKO DM6420HR_CLK1 and DM6420HR_CLK2 Counter divisor value Success Failure with errno set as follows descriptor refers to a file that is open but not for write access Timer is not valid This function makes use of several ioctl requests ClockMode6420 int ClockMode6420 int descriptor enum DM6420HR_CLK Timer enum DM6420HR_CLK_MODE Mode J DM6420 Driver for Linux 18 Description Set the mode of the specified counter on the 8254 chip This function also sets the indicated counter to receive a subsequent divisor load least significant byte first then most significant byte Parameters descriptor File descriptor from OpenBoard6420 call Timer Indicates which counter to use Valid values are DM6420HR_CLKO DM6420HR_CLK1 and DM6420HR_CLK2 Mode Indicates which clock mode to set Valid values are DM6420HR_CLK_MODE0 DM6420HR_CLK_MODE1 DM6420HR_CLK_MODE2 DM6420HR_CLK_MODE3 DM6420HR_CLK_MODE4 and DM6420HR_CLK_MODES Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Timer is not valid EINVAL Mode is not
74. ss EFAULT buffer_p is not a valid user address EINVAL from_register is not valid EINVAL type is not valid EOPNOTSUPP from_register is rSTR_AD_6420 and type is DM6420HR_STR_TYPE_BYTE EOPNOTSUPP from_register is rSTR_DIN_FIFO_6420 and type is DM6420HR_STR_TYPE_WORD IOCTL Interface int rc struct DM6420HR_GID io_request intl6_t ad_buffer 600 uint8_t digital_buffer 512 Read from A D input FIFO af 10_request port rSTR_AD_6420 Transfer 16 bit values 10_request type DM6420HR_STR_TYPE_WORD Transfer data into ad_buffer array io_request buf void amp ad_buffer 0 45 DM6420 Driver for Linux Transfer 600 16 bit values 10_request times 600 rc ioctl descriptor DM6420HR_IOCTL_DMA_GETINC amp io_request Read from digital port 0 input FIFO io_request port rSTR_DIN_FIFO_6420 Transfer 8 bit values io_request type DM6420HR_STR_TYPE_BYTE Transfer data into digital_buffer array io_request buf void amp digital_buffer 0 Transfer 512 8 bit values 10_request times 512 rc ioctl descriptor DM6420HR_IOCTL_DMA_GETINC amp io_request GetDmaData6420 int GetDmaData6420 int descriptor void dma_buffer_p enum DM6420HR_DMA DMAChannel size_t length size_t offset size_t bytes_transferred_p Description Copy data from specified DMA circuit s DMA buffer into user buffer
75. st Write to Trigger Mode Register at base I O address 6 io_request reg r_TRIGGER_6420 Only change bit 9 in register 10_request mask OXFDFF Set internal pacer clock er i0_request value 0 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request DM6420 Driver for Linux 90 SetPauseEnable6420 int SetPauseEnable6420 int descriptor int Enable Description Enable or disable a board s A D table pause bit Parameters descriptor File descriptor from OpenBoard6420 call Enable Flag to indicate whether the A D table pause bit should set A value of 0 means enable the pause bit A nonzero value means disable the pause bit Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access IOCTL Interface int rc struct DM6420HR_MIO16 io_request Write to Control Register at base I O address 2 io_request reg r CONTROL_6420 Only change bit 8 in register io_request mask OXFEFF Activate pause bit in A D table channel gain scan memory 3 io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_MOUTW amp io_request mo 2M 6420 Driver for Linux SetSampleCounterStop6420 int SetSampleCounterStop6420 int descriptor int Disable Description Enable or disable a board s A D Sample Counter Stop Parameters descriptor File descriptor from OpenBoa
76. t you can then move the resulting object files libraries and executables to the production system s Building the driver consists of several steps 1 compiling the source code 2 loading the resulting kernel module into the kernel and 3 creating hardware device files in the dev directory To perform any of the above steps you must change your current directory to driver The file Makefile contains rules to assist you DM6420 Driver for Linux 6 To compile the source code issue the command make This command will create the driver object file The name of the driver object file depends on the version of the kernel being used If compiling with a 2 4 kernel the filename will be rtd dm6420 0 and if compiling with a 2 6 kernel the filename will be rtd dm6420 ko The GNU C compiler gcc is used to build the driver code Before the driver can be used it must be loaded into the currently running kernel Using the command make insmod will load the DM6420 driver into the kernel This target assumes that A single DM6420 is installed The board s base I O address is set to the factory default of 0x300 The DM6420 will use IRQs 3 and 5 The board will use DMA channels 5 and 6 If the previous assumptions do not match your hardware setup you will need to edit the Makefile and change this rule to reflect your board configuration or manually issue an appropriate insmod command When you load the kernel driver you might
77. tl descriptor DM6420HR_IOCTL_MOUTW amp io_request SetPacerClock6420 int SetPacerClock6420 int descriptor double clock double actual_p Description Set a board s pacer clock rate This function decides whether to use a 16 bit or 32 bit clock depending upon the clock rate Parameters descriptor Clock Actual_p Return Value 0 1 EACCES EINVAL EINVAL EINVAL IOCTL Interface File descriptor from OpenBoard6420 call Clock rate desired Address where the actual programmed frequency should be stored If this function fails the actual frequency is not updated Success Failure with errno set as follows descriptor refers to a file that is open but not for write access clock is greater than 8 MHz clock is 0 0 clock is less than 0 0 This function makes use of several ioctl requests 89 DM6420 Driver for Linux SetPacerClockSource6420 int SetPacerClockSource6420 int descriptor enum DM6420HR_PACER_CLK Source Description Select the source of a board s pacer clock Parameters descriptor File descriptor from OpenBoard6420 call Source Pacer clock source Valid values are DM6420HR_PACER_CLK_INTERNAL and DM6420HR_PACER_CLK_ EXTERNAL Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for write access EINVAL Source is not valid IOCTL Interface int rc struct DM6420HR_MIO16 io_reque
78. tor File descriptor from OpenBoard6420 call DM6420 Driver for Linux 26 Irg_enabled_p Address where IRQ enabled flag should be stored If digital interrupts are enabled a nonzero value will be stored here Otherwise O will be stored here Return Value 0 Success 1 Failure with errno set as follows EACCES descriptor refers to a file that is open but not for read access IOCTL Interface int rc struct DM6420HR_IO8 io_request Read from the Digital IRQ Strobe Status Register at base I O address 30 io_request reg r_DIO_STATUS_6420 Any value works here because it is ignored making this request However on return from ioctl the member variable value contains the byte read io_request value 0 rc ioctl descriptor DM6420HR_IOCTL_INB amp io_request if re 1 Tf bit 4 is cleared in Status Register digital I O interrupts are disabled ai if io_request value amp 0x10 0 fprintf stdout Digital I O interrupts disabled n DIOIsChipIRQEventMode6420 int DIOIsChipIRQEventMode6420 int descriptor int irq_event_p Description Determine whether or not a board s digital interrupt mode is set to event mM 6420 Driver for Linux Parameters descriptor File descriptor from OpenBoard6420 call Irq_event_p Address where IRQ event mode flag should be stored If digital interrupts are in event mode a nonzero value will be stored her

DM6420 Driver for Linux User`s Manual Version 2.01.xx

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