CU20025ECPB-W1J Application Note
Contents
1. VFD can be configured to interface to 180 bus WR RD via the jumpers that are located on the printed circuit board To short circuit the jumpers a soldering iron will be necessary and a sharp object such as a knife is required 1 2 8 Bit 4 Bit Selection In both the M68 and i80 interface modes the data bus width can be selected for 8 bit or 4 bit operation The modes are switched from 8 bit to 4 bit by sending a software command If you have chosen the 4 bit mode use the upper nibble D7 D4 An example of the initialization sequence for each case will be explained in detail in the next section 2 Initializing Procedure The U version module has its BUS width set at 8 bits by default The U version allows the user to select either 8 bits or 4 bits 4 bits mode allows the users to take advantage of the LCD interchangeable function 2 1 8 bit mode 1 Wait 260m Sec After Vec gt 4 75 Power on reset 2 Function Set 38H RS 0 8 bit Bus Mode 3 Function Set 38H RS 0 8 bit Bus Mode 4 Brightness Set OOH RS 1 100 Brightness 5 Display OFF 08H RS 0 Display OFF Cursor OFF Blinking OFF 6 Display Clear 01H RS 0 Display Clear Instruction 7 Wait 2 3m Sec 8 Display ON OCH RS 0 Display ON Cursor OFF Blinking OFF 9 Entry Mode 06H RS 0 Cursor Increment Page 2 of 2 Downloaded from Elcodis com electronic components distributor Nortlahe itron APPLICATION NOTES APN 1100 01 2 2 4 bi2. FD resulting in longer tube life Typical power consumption when the display is turned off is approximately 5mA 4 7 Do I need to detect the display after Display OFF command ON OFF is controlled by the controller not the circuit therefore there is no need to detect the display 4 7 1 How do you monitor the current consumption The current consumption depends on the state of the display on or off and can vary from 5mA to several hundreds of mA 5 What is the difference between CU20025ECPB W1J module and LCD CU20025ECPB W1J LCD General BUS Interface M68 and i80 M68 only CG RAM SIZE 320 bit 512 bit CGROM Font 240 characters 192 characters No of Lines 2 lines 1 line or 2 lines Brightness Control 4 level brightness control function Address Data hold time Min 700ns Min 20ns RS R W set up time Min 20ns Min 140ns Data Delay From E and WR Max 160ns Max 320ns Execution Time Faster than LCD except Display Clear Slower than LCD except Display Clear Reset C R delay reset circuit 100ms typical No delay circuit Safety Information The glass portion is exposed on VFD Caution is advised when handling VFD Please read the user s manual and the specifications before using the product Downloaded from Elcodis com electronic components distributor Page 6 of 6
3. Nortlahe itran Revised Date Feb 03 2009 APPLICATION NOTES Issued Date Feb 04 2008 APN 1100 01 ortlare itron CU20025ECPB WI1J Application Note INDEX 1 BUS Setup 2 Initializing procedure 3 DDRAM address for CU20025ECPB W1J 4 FAQ Frequently Asked Questions 5 Comparisons between U version modules and LCDs Noritake Co Inc East Coast Midwest West Coast Atlanta Chicago amp Dallas LA 2635 Clearbrook Drive 888 326 3423 800 779 5846 888 795 3423 Arlington Height IL 60005 New Jersey www noritake elec com 888 296 3423 Phone 800 779 5846 Fax 847 593 2285 Page 1 of 1 Downloaded from Elcodis com electronic components distributor Norilahe itron APPLICATION NOTES APN 1100 01 The fran is the registered trademark of Noritake Vacuum Fluorescent Display VFD This Application Note has been compiled as a support material for our customers using U version Vacuum Fluorescent Display Modules described as U version Modules in the following sections This document contains general product information the user is recommended to refer to the most recent product specification Materials included in this document are meant to be reference data and actual results may vary Applicable Model CU20025ECPB W1J 1 BUS Setup 1 1 M68 i80 Selection The U version VFD modules support an M68 interface bus E amp R W making it interchangeable with LCDs In addition the U version
4. character overlap The character overlap is not visible on a LCD due to their slow response time but can be visible on a VFD because of its high response time To prevent this character overlap when writing to the module the high period of the E signal should be 5usec or less Downloaded from Elcodis com electronic components distributor Page 3 of 3 Nortlahe itron APPLICATION NOTES APN 1100 01 4 2 Where can I purchase the Optical Filters Pre packaged Optical Filter and VFD set are available at Noritake Co Inc 2635 Clearbrook Drive Arlington Heights IL 60005 www noritake elec com Phone 800 779 5846 Fax 847 593 2285 Optical Filter information can be found at www noritake elec com NTC color_filter htm 4 3 Where can I purchase the Noritake VFD Please contact our sales representatives near you East Coast Midwest West Coast Atlanta Chicago amp Dallas LA 888 326 3423 800 779 5846 888 795 3423 New Jersey 888 296 3423 4 4 Why do 4 characters show up on the screen when only one character is entered It is likely that the control signals especially E contains noise caused by the length of the cable and as a result a single write cycle is interpreted as multiple write cycles To prevent this from happening observe the waveform of E signal with an oscilloscope for overshoot or undershoot Other solutions Method 1 A series resistance of 100 ohms is
5. inserted on the controller side If the module is operated in the i80 mode insert it for WR Controller V v Module Resistance Method 2 Connect the cable with a diode termination on the E Signal Page 4 of 4 Downloaded from Elcodis com electronic components distributor Norilahe itron APPLICATION NOTES APN 1100 01 A resistor with a value of 100 to 200 ohms is connected at ground Resistor with value of 200 to 600 ohms is connected at 5V 5V Host Controller Module GND OR SV Host Controller Module GND Note High speed controller function can distort the waveform causing the signals to be processed as multiple signals 4 5 Comparison of In Rush Current The in rush current for the CU20025ECPB W1J follows Product Model Rush Current Peak value A Sustained Period ms CU20025ECPB W1J Approx 1 5 Approx 0 4 Sustained time is measured from the time in rush current starts and until it falls to half the peak value 4 6 Sleep Mode Reducing the Power Consumption Page 5 of 5 Downloaded from Elcodis com electronic components distributor Nortlahe itron APPLICATION NOTES APN 1100 01 Sleep mode allows the U version modules to reduce the power consumption Sleep mode is especially beneficial when used in a battery application Sleep mode is activated when Display On Off command is sent Sleep mode stops the DC DC converter and cut off filament power to the V
6. t mode Wait 260m Sec After VCC gt 4 75 1 2 3 4 5 6 7 8 9 10 Display ON OFF Function Set Function Set Function Set Function Set Brightness Set Display OFF Display Clear Wait 2 3m Sec 11 Entry Mode Note In order to establish synchronization between the upper and the lower nibble the U version module should be first set in 8 bit mode To ensure synchronization we advise that the task to be performed three times 3xH RS 0 3xH RS 0 2xH 8xH RS 0 OxH OxH RS 0 OxH 8xH RS 1 OxH 8xH RS 0 OxH 1xH RS 0 OxH CxH RS 0 OxH 6xH RS 0 3 Display Data RAM Addresses for CU20025ECPB W 1J Before writing the 2 line on to CU20025ECPB W1 J the RAM address pointer needs to be reassigned The U version module has 80 character capacities for the display data RAM Power on reset 8 bit Bus Mode 8 bit Bus Mode 8 bit Bus Mode Set 4 bit Bus Mode 100 Brightness Display OFF Cursor OFF Blinking OFF Display Clear Display ON Cursor OFF Blinking OFF Cursor Increment Modules with less than 80 displayed characters use selected area of the RAM for each row These selected areas are specified by the address assignment 3 1 CU20025ECPB W1J Address assignment as follows 00H 01H 12H 13H 40H 41H 52H 53H LEFT OOO RIGHT 4 FAQ 4 1 When a character is rewritten or scrolled on U version module why does the
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