V850ES/Fx2 - RS Components International
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1. AFCAN Sleep Mode Wakeup Specification change notice 4 2 Other WAKEUP Handling Hints 4 2 1 Switching off the Clock Supply to AFCAN while in SLEEP Mode If the clock supply to the AFCAN macro is stopped while it is in SLEEP mode the synchronisa tion of the WAKEUP works without any restriction To achieve this the documentation of clock controlling unit of the target device should be consulted Usually this is performed by setting the STOP mode of the CPU of the target device However the user has to consider that there must not be any WAKEUP condition dominant level on the CAN Bus while the software is executing between setting SLEEP mode and stopping the AFCAN clock 4 2 2 Using a Waiting Loop within the WAKEUP interrupt routine Within the WAKEUP interrupt routine create a waiting loop which tests the capability of clearing the WAKEUP interrupt flag within AFCAN by checking the actual power save mode In the following C code example replace the objects in lt gt brackets by the hardware locations within your implementation Use the appropriate access types as described in the User s Manual do AFCAN_SleepStatus lt CnCTRL_PSMODE gt if AFCAN_SleepStatus 0 macro is still in SLEEP mode waiting for latency time lt CnINTS_CINTS5 gt 1 repeated trying to clear CINTSS while AFCAN_SleepStatus 0 This improvement hint cannot be applied if a CAN Bus Transceive2. CAN bus activity Releasing AFCAN sleep mode After detected dominant edge After detected dominant edge by user PSMODEO 0 PSMODEO 0 1 CINTS5 1 CINTS5 1 Clear PSMODEO bit Additional Measure commun Clear PSMODEO bit 3 2 Not affected Applications 3 2 1 Applications not using SLEEP mode If SLEEP mode is not used this Operating Precaution is not applicable 3 2 2 Applications waking up from SLEEP mode by User Request only If there is no condition when SLEEP mode can be left by CAN Bus activity but only on User Request by clearing the PSMODE flag by software this Operating Precaution is not applica ble 3 2 3 Applications using a CPU Power Save Mode If the clock to the AFCAN macro is disabled while it is waken up from SLEEP mode this operat ing precaution is not applicable This means if the user selects a power save mode of the target device which switches off the clock of the AFCAN macro immediately after it had been set into SLEEP mode like the CPU STOP mode the precaution needs not to be considered This is associated with the software improvement hints below Customer Notification TPS HE B 2590 7 No 1 Operating Precautions for V850ES Fx2 AFCAN Sleep Mode Wakeup Specification change notice 3 3 Affected Applications 3 3 1 Applications not waiting until SLEEP mode is left If bus transceivers are used in conjunction with AFCAN which will propagate the CA
3. Party vendors worldwide as their own product or on contract from NEC 2 Customer Notification TPS HE B 2590 Operating Precautions for V850ES Fx2 A B C D Table of Operating Precautions Description of O perating Precautions Valid Specification amp 425 t x xx RRRXERERLUSE sauna Revision History Customer Notification TPS HE B 2590 Operating Precautions for V850ES Fx2 Customer Notification TPS HE B 2590 Operating Precautions for V850ES Fx2 A Table of Operating Precautions UPD70F323x UPD70323x Rev Outline RankNote AFCAN Sleep Mode Wakeup Specification change notice V Notapplicable X Applicable Note The rank is indicated by the letter appearing at the 5th position from the left in the lot number marked on each product Customer Notification TPS HE B 2590 5 Operating Precautions for V850ES Fx2 B Description of Operating Precautions AFCAN Sleep Mode Wakeup Specification change notice 1 Description When the AFCAN macro is set into SLEEP mode it can be waken up by CAN bus activity This waking up is asynchronous to the operation of the macro and the CPU By configuration set ting a WAKEUP interrupt can be generated by the AFCAN macro on the wakeup event While the interrupt is generated asynchronously the AFCAN macro may need another dominant edge on the CAN
4. bus or software clearing of the SLEEP mode in order to restart its synchronous operation During the time after the interrupt already has been indicated and before the CAN macro has restarted its synchronous operation the registers of the AFCAN macro will not operate because the AFCAN macro still remains in SLEEP mode This time we will refer to as wakeup dead time in the following context To resolve from the wakeup dead time software and or hardware measures are required 2 Exclusions This Operating Precaution is only applicable to applications which are fulfilling at least one of the following three conditions SLEEP Mode of AFCAN is used and the possibility to wake up AFCAN by CAN Bus events is given see remark 1 below During SLEEP mode of the AFCAN macro a CAN Bus wakeup condition occurs while the AFCAN macro is supplied with clock see remark 2 below and after waking up from SLEEP mode of the AFCAN macro the application software does not wait until the SLEEP mode is released by polling the CnCTRL PSMODE register before continuing operation with the AFCAN macro see remark 3 below and the CPU can reach instructions where AFCAN registers are accessed while the AFCAN macro is still in SLEEP mode due to the missing waiting condition During SLEEP mode of the AFCAN macro a CAN Bus wakeup condition occurs while the AFCAN macro is supplied with clock see remark 2 below and after waking up from SLEEP
5. N bus signal to AFCAN permanently not switched off or not in power saving modes or if bus transceivers are used in conjunction with AFCAN which will propagate the unmodified CAN Bus signal when wak ing up from a power save mode the wakeup dead time lasts from the first recessive to dominant edge of the CAN Bus signal which generates the wake up until the next recessive to dominant edge of the CAN Bus signal The worst case maximum length of the wakeup dead time is given by the CAN bus speed and the rule of the CAN bus about the frequency of recessive to dominant edges Given by the stuff ing rule at least every 10 bits a recessive to dominant edge must occur If during the wakeup dead time the CPU waits until the SLEEP mode is indicated to be cleared either by polling the PSMODE flag or by retrying to clear CnINTS 5 this operating precau tion is not applicable In this case the improvement hint according to 4 2 2 is followed implicitly If during the wakeup dead time the CPU does not perform any access to the AFCAN macro in any case this operating precaution is not applicable 3 3 2 Applications using Bus Transceivers generating long lasting dominant CAN Bus Signals If bus transceivers are used in conjunction with AFCAN which generate a permanent or long last ing dominant level when waking up from a power save mode the operating precaution must be considered in any case In this case the wakeup dead time lasts from the
6. NEC Customer Notification V850ES Fx2 32 bit Single Chip Microcontrollers Operating Precautions uPD70F323x uPD70323x Document No TPS HE B 2590 Date Published August 2006 NEC Electronics Europe GmbH DISCLAIMER The related documents in this customer notification may include preliminary versions However preliminary versions may not have been marked as such The information in this customer notification is current as of its date of publication The information is subject to change without notice For actual design in refer to the latest publications of NEC s data sheets or data books etc for the most up to date specifications of NEC PRODUCT S Not all PRODUCT S and or types are available in every country Please check with an NEC sales representative for availability and additional information No part of this customer notification may be copied or reproduced in any form or by any means without prior written consent of NEC NEC assumes no responsibility for any errors that may appear in this customer notification NEC does not assume any liability for infringement of patents copyrights or other intellectual property rights of third parties by or arising from the use of NEC PRODUCT S listed in this customer notification or any other liability arising from the use of such PRODUCT S No license express implied or otherwise is granted under any patents copyrights or other intellectual property rights of NEC or oth
7. er under this Operating Precaution document without the possibility of recourse to the Conflicts Law or the law of gth July 1989 relating to the UN Convention on Contracts for the International Sale of Goods the Vienna CISG agreement D sseldorf is the court of jurisdiction for all legal disputes arising directly or indirectly from this information NEC is also entitled to make a claim against the Customer at his general court of jurisdiction If the supplied goods information are subject to German European and or North American export controls the Customer shall comply with the relevant export control regulations in the event that the goods are exported and or re exported If deliveries are exported without payment of duty at the request of the Customer the Customer accepts liability for any subsequent customs administration claims with respect to NEC Notes 1 NEC as used in this statement means NEC Electronics Corporation and also includes its direct or indirect owned or controlled subsidiaries 2 PRODUCT S means NEC semiconductor products NEC semiconductor products means any semiconductor product developed or manufactured by or for NEC and or TOOLS TOOLS means hardware and or software development tools for NEC semiconductor products developed manufactured and supplied by NEC and or hardware and or software development tools supplied by NEC but developed and or manufactured by independent gd
8. ers Descriptions of circuits software and other related information in this customer notification are provided for illustrative purposes of PRODUCT S operation and or application examples only The incorporation of these circuits software and information in the design of customer s equipment shall be done under the full responsibility of customer NEC assumes no responsibility for any losses incurred by customers or third parties arising from the use of these circuits software and information While wherever feasible NEC endeavors to enhance the quality reliability and safe operation of PRODUCT S the customer agree and acknowledge that the possibility of defects and or erroneous thereof cannot be eliminated entirely To minimize risks of damage to property or injury including death to persons arising from defects and or errors in PRODUCT S the customer must incorporate sufficient safety measures in their design such as redundancy fire containment and anti failure features The customer agrees to indemnify NEC against and hold NEC harmless from any and all consequences of any and all claims suits actions or demands asserted against NEC made by a third party for damages caused by one or more of the items listed in the enclosed table of content of this customer notification for PRODUCT S supplied after the date of publication Applicable Law The law of the Federal Republic of Germany applies to all information provided by NEC to the Custom
9. first recessive to dominant edge of the CAN bus signal which generates the wake up until the next recessive to dominant edge of the CAN bus signal depending on the behaviour of the CAN bus transceiver If no further dominant edge on the CAN bus occurs in case of some CAN transceivers which only provide one single edge on waking up the time until SLEEP mode is left may become end less Therefore the waking up procedure of AFCAN regarding software must be adjusted accord ing to 4 1 1 4 Software Improvement Hints 4 1 Recommended WAKEUP Handling by Software 4 1 1 Clearing the SLEEP Mode by Software Within the WAKEUP interrupt routine before accessing any other register or area of AFCAN the SLEEP mode can be canceled by software followed by a clearance of the WAKEUP interrupt flag Doing so the AFCAN macro will start its synchronous operation right after these accesses In the following C code example replace the objects in lt gt brackets by the hardware locations within your implementation Use the appropriate access types as described in the User s Manual WAKEUP INTERRUPT VECTOR gt CnCTRL PSMODE 0 Clear SLEEP Mode CnINTS CINTS5 1 Clear INTS5 following other parts of interrupt routine Remark Clearing INTS5 is required to get another WAKEUP interrupt anyway by specification Customer Notification TPS HE B 2590 No 1 Operating Precautions for V850ES Fx2
10. mode of the AFCAN macro the CAN Bus Transceiver generates a long lasting or permanent dominant level to the CRXD input of the AFCAN macro instead of the propagated CAN Bus level Remarks 1 If the CAN Bus Transceiver does not propagate the CAN Bus signal while the AFCAN macro is in SLEEP mode and also does not forward a wakeup signal to CRXD this Operating Precaution is not applicable 2 The clock supply to the AFCAN macro can be stopped depending on the features of the device and the system design of the application If the clock supply to the AFCAN macro is stopped while a wakeup condition occurs this Operating Pre caution is not applicable 3 The maximum waiting time for this loop can be up to 10 bits of the CAN Bus Baudrate Waiting while retrying to clear CnINTS Bit 5 can be used alternatively All other applications are not affected by this Operating Precaution Customer Notification TPS HE B 2590 Operating Precautions for V850ES Fx2 AFCAN Sleep Mode Wakeup Specification change notice 3 Application Dependency 3 1 Overview The following flowchart illustrates how and whether additional measures have to be taken in soft ware to avoid the wakeup dead time Figure Additional Measures in case AFCAN clock is active when waking up AFCAN sleep mode In case AFCAN Clock is disabled In case AFCAN Clock is active Releasing AFCAN sleep mode Releasing AFCAN sleep mode by CAN bus activity by
11. r is attached to AFCAN which generates a permanent or long lasting dominant level to the FCRXDn receive input pin if a wakeup condition occurs Missing another dominant edge on the bus the synchronisation will not happen and the loop could run endlessly 4 2 3 Using INIT Mode instead of SLEEP Mode In this case the waking up by CAN bus activity must be performed via another free external inter rupt The CAN receive signal must be distributed on the FCRXDn pin and to another external interrupt pin in parallel Using this external interrupt the AFCAN macro can be restored into the previous operation mode This implementation will not use the SLEEP mode of AFCAN at all and use the INIT mode instead Customer Notification TPS HE B 2590 9 Operating Precautions for V850ES Fx2 C Valid Specification Date pulished Document No Document Title November 2005 U17830EE1VOUMOO V850ES Fx2 Hardware Users Manual December 2005 U17830EE1VOUMOO Errata Sheet for V850ES Fx2 Hardware User s Manual November 2004 U17834EE1VODS00 Data Sheet for V850ES FE2 April 2006 U17833EE3V0DS00 Data Sheet for V850ES FF2 November 2005 U17832EE1VODS00 Data Sheet for V850ES FG2 November 2005 U17831EE1VODSO00 Data Sheet for VBBOES FJ2 10 Customer Notification TPS HE B 2590 Operating Precautions for V850ES Fx2 D Revision History Date pulished Document No Comment August 2006 TPS HE B 2590 New List Cu
12. stomer Notification TPS HE B 2590 11
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