Keywords: LED display drivers, LED drivers, display drivers, SPI, serial, blink, 3V
Related Parts 


QuickStart: Driving 7Segment Displays with the MAX6954 
Digit  O0  O1  O2  O3  O4  O5  O6  O7  O8  O9  O10  O11  O12  O13  O14  O15  O16  O17  O18 
0 0a 
CC0  1a  1b  1c  1d  1dp  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
1, 1a 
CC1  1a  1b  1c  1d  1dp  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
2, 2a 
1a  CC2  1b  1c  1d  1dp  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
3 3a 
1a  CC3  1b  1c  1d  1dp  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
4 4a 
1a  1b  1c  CC4  1d  1dp  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
5 5a 
1a  1b  1c  CC5  1d  1dp  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
6, 6a 
1a  1b  1c  1d  1dp  CC6  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp  
7, 7a 
1a  1b  1c  1d  1dp  CC7  1e  1f  1g  2a  2b  2c  2d  2e  2f  2g  2dp 
REGISTER  POWERUP CONDITION  ADDRESS (HEX) 
REGISTER DATA  
D7  D6  D5  D4  D3  D2  D1  D0  
Decode Mode  7segment font enabled  0x01  1  1  1  1  1  1  1  1 
Global Intensity  1/16 (minimum intensity)  0x02  X  X  X  X  0  0  0  0 
Scan Limit  Display sixteen 7segment digits: 0, 1, 2, 3, 4, 5, 6, 7, 0a, 1a, 2a, 3a, 4a, 5a, 6a, 7a  0x03  X  X  X  X  X  1  1  1 
Control Register  Shutdown enabled, blink disabled, blink speed is slow  0x04  0  0  X  X  0  0  0  0 
Display Test  Normal operation (display test disabled)  0x07  X  X  X  X  X  X  X  0 
Digit Type  Digits 0 through 7 are 7 segment digits  0x0C  0  0  0  0  0  0  0  0 
Intensity10  1/16 (min on), digits 1 and 0  0x10  0  0  0  0  0  0  0  0 
Intensity32  1/16 (min on), digits 3 and 2  0x11  0  0  0  0  0  0  0  0 
Intensity54  1/16 (min on), digits 5 and 4  0x12  0  0  0  0  0  0  0  0 
Intensity76  1/16 (min on), digits 7 and 6  0x13  0  0  0  0  0  0  0  0 
Intensity10a  1/16 (min on), digits 1a and 0a  0x14  0  0  0  0  0  0  0  0 
Intensity32a  1/16 (min on), digits 3a and 2a  0x15  0  0  0  0  0  0  0  0 
Intensity54a  1/16 (min on), digits 5a and 4a  0x16  0  0  0  0  0  0  0  0 
Intensity76a  1/16 (min on), digits 7a and 6a  0x17  0  0  0  0  0  0  0  0 
Digit 0  Blank digit, both planes  0x60  0  0  1  0  0  0  0  0 
Digit 1  Blank digit, both planes  0x61  0  0  1  0  0  0  0  0 
Digit 2  Blank digit, both planes  0x62  0  0  1  0  0  0  0  0 
Digit 3  Blank digit, both planes  0x63  0  0  1  0  0  0  0  0 
Digit 4  Blank digit, both planes  0x64  0  0  1  0  0  0  0  0 
Digit 5  Blank digit, both planes  0x65  0  0  1  0  0  0  0  0 
Digit 6  Blank digit, both planes  0x66  0  0  1  0  0  0  0  0 
Digit 7  Blank digit, both planes  0x67  0  0  1  0  0  0  0  0 
Digit 0a  Blank digit, both planes  0x68  0  0  1  0  0  0  0  0 
Digit 1a  Blank digit, both planes  0x69  0  0  1  0  0  0  0  0 
Digit 2a  Blank digit, both planes  0x6A  0  0  1  0  0  0  0  0 
Digit 3a  Blank digit, both planes  0x6B  0  0  1  0  0  0  0  0 
Digit 4a  Blank digit, both planes  0x6C  0  0  1  0  0  0  0  0 
Digit 5a  Blank digit, both planes  0x6D  0  0  1  0  0  0  0  0 
Digit 6a  Blank digit, both planes  0x6E  0  0  1  0  0  0  0  0 
Digit 7a  Blank digit, both planes  0x6F  0  0  1  0  0  0  0  0 
CONFIGURATION REGISTER DATA BIT 
DATA BIT LABEL  STATE  FUNCTION 
D7  P  0  P1 Blink Phase 
D6  I  0  Intensity for all digits is controlled by one setting in the Global Intensity Register 
1  Intensity for digits is controlled by the individual settings in the Intensity10 through Intensity76a registers.  
D5  R  0  Digit data for both planes P0 and P1 are unaffected 
1  Digit data for both planes P0 and P1 are cleared on the rising edge of activelow CS  
D4  T  0  Blink timing counters are unaffected. 
1  Blink timing counters are reset on the rising edge of activelow CS.  
D3  E  0  Blink function disabled 
1  Blink function enabled  
D2  B  0  Slow Blinking. Segments blink on for 1s, off for 1s with fOSC = 4MHz. 
1  Fast Blinking. Segments blink on for 0.5s, off for 0.5s with fOSC = 4MHz.  
D1  X  X  Don't care 
D0  S  0  Shutdown 
1  Normal Operation 
MODE  ADDRESS CODE (HEX)  REGISTER DATA  
D7  D6  D5  D4  D3  D2  D1  D0  
7segment mode, writing digit data to use font map data with decimal place unlit  0x20 to 0x2F 0x40 to 0x4F 0x60 to 0x6F 
0  Bits D6 to D0 select font character  
7segment mode, writing digit data to use font map data with decimal place lit  0x20 to 0x2F 0x40 to 0x4F 0x60 to 0x6F  1  Bits D6 to D0 select font character 
REGISTER ADDRESS (HEX)  DIGIT  CHARACTER  FONT MAP EQUIVALENT CODE  
DECIMAL  HEX  
0x20  0  C  0000 1100  0x0C 
0x28  0a  A  0000 1001  0x0A 
0x21  1  1  0000 0001  0x01 
0x29  1a  1  0000 0001  0x01 
0x23  3  8  0000 1000  0x08 
0x2B  3a  0  0000 0000  0x00 
0x24  4  0  1000 0000  0x80 
0x2C  4a  6  0000 0110  0x06 
0x25  5  2  0000 0010  0x02 
0x2D  5a  9  1000 1001  0x89 
0x26  6  4  0000 0100  0x04 
0x2E  6a  6  0000 0110  0x06 
0x27  7  4  0000 0100  0x04 
0x2F  7a  2  0000 0010  0x02 
REGISTER (HEX) 
COMMAND (HEX) 
FUNCTION 
0x07  0x01  Enter display test mode 
0x07  0x00  Exit display test mode 
0x04  0x01  Exit shutdown mode, disable blinking and select global intensity control 
0x20  0x0C  Write "C" to digit 0 
0x28  0x0A  Write "A" to digit 0a 
0x21  0x01  Write "1" to digit 1 
0x29  0x01  Write "1" to digit 1a 
0x23  0x08  Write "8" to digit 3 
0x2B  0x00  Write "0" to digit 3a 
0x24  0x80  Write "0." to digit 4 
0x2C  0x06  Write "6" to digit 4a 
0x25  0x02  Write "2" to digit 5 
0x2D  0x89  Write "9." to digit 5a 
0x26  0x04  Write "4" to digit 6 
0x2E  0x06  Write "6" to digit 6a 
0x27  0x04  Write "4" to digit 7 
0x2F  0x02  Write "2" to digit 7a 
0x02  0xFF  Set global intensity to fullscale 
REGISTER  ADDRESS (COMMAND BYTE)  ADDRESS (HEX CODE) 

D15  D14  D13  D12  D11  D10  D9  D8  
Decode Mode  R/activelow W  0  0  0  0  0  0  1  0x01 
Global Intensity  R/activelow W  0  0  0  0  0  1  0  0x02 
Scan Limit  R/activelow W  0  0  0  0  0  1  1  0x03 
Configuration  R/activelow W  0  0  0  0  1  0  0  0x04 
Display Test  R/activelow W  0  0  0  0  1  1  1  0x07 
Digit Type  R/activelow W  0  0  0  1  1  0  0  0x0C 
Intensity 10  R/activelow W  0  0  1  0  0  0  0  0x10 
Intensity 32  R/activelow W  0  0  1  0  0  0  1  0x11 
Intensity 54  R/activelow W  0  0  1  0  0  1  0  0x12 
Intensity 76  R/activelow W  0  0  1  0  0  1  1  0x13 
Intensity 10a  R/activelow W  0  0  1  0  1  0  0  0x14 
Intensity 32a  R/activelow W  0  0  1  0  1  0  1  0x15 
Intensity 54a  R/activelow W  0  0  1  0  1  1  0  0x16 
Intensity 76a  R/activelow W  0  0  1  0  1  1  1  0x17 
Digit 0 Plane P0  R/activelow W  0  1  0  0  0  0  0  0x20 
Digit 1 Plane P0  R/activelow W  0  1  0  0  0  0  1  0x21 
Digit 2 Plane P0  R/activelow W  0  1  0  0  0  1  0  0x22 
Digit 3 Plane P0  R/activelow W  0  1  0  0  0  1  1  0x23 
Digit 4 Plane P0  R/activelow W  0  1  0  0  1  0  0  0x24 
Digit 5 Plane P0  R/activelow W  0  1  0  0  1  0  1  0x25 
Digit 6 Plane P0  R/activelow W  0  1  0  0  1  1  0  0x26 
Digit 7 Plane P0  R/activelow W  0  1  0  0  1  1  1  0x27 
Digit 0a Plane P0  R/activelow W  0  1  0  1  0  0  0  0x28 
Digit 1a Plane P0  R/activelow W  0  1  0  1  0  0  1  0x29 
Digit 2a Plane P0  R/activelow W  0  1  0  1  0  1  0  0x2A 
Digit 3a Plane P0  R/activelow W  0  1  0  1  0  1  1  0x2B 
Digit 4a Plane P0  R/activelow W  0  1  0  1  1  0  0  0x2C 
Digit 5a Plane P0  R/activelow W  0  1  0  1  1  0  1  0x2D 
Digit 6a Plane P0  R/activelow W  0  1  0  1  1  1  0  0x2E 
Digit 7a Plane P0  R/activelow W  0  1  0  1  1  1  1  0x2F 
Digit 0 Plane P1  R/activelow W  1  0  0  0  0  0  0  0x40 
Digit 1 Plane P1  R/activelow W  1  0  0  0  0  0  1  0x41 
Digit 2 Plane P1  R/activelow W  1  0  0  0  0  1  0  0x42 
Digit 3 Plane P1  R/activelow W  1  0  0  0  0  1  1  0x43 
Digit 4 Plane P1  R/activelow W  1  0  0  0  1  0  0  0x44 
Digit 5 Plane P1  R/activelow W  1  0  0  0  1  0  1  0x45 
Digit 6 Plane P1  R/activelow W  1  0  0  0  1  1  0  0x46 
Digit 7 Plane P1  R/activelow W  1  0  0  0  1  1  1  0x47 
Digit 0a Plane P1  R/activelow W  1  0  0  1  0  0  0  0x48 
Digit 1a Plane P1  R/activelow W  1  0  0  1  0  0  1  0x49 
Digit 2a Plane P1  R/activelow W  1  0  0  1  0  1  0  0x4A 
Digit 3a Plane P1  R/activelow W  1  0  0  1  0  1  1  0x4B 
Digit 4a Plane P1  R/activelow W  1  0  0  1  1  0  0  0x4C 
Digit 5a Plane P1  R/activelow W  1  0  0  1  1  0  1  04D 
Digit 6a Plane P1  R/activelow W  1  0  0  1  1  1  0  0x4E 
Digit 7a Plane P1  R/activelow W  1  0  0  1  1  1  1  0x4F 
Related Parts  
MAX6954  4Wire Interfaced, 2.7V to 5.5V LED Display Driver with I/O Expander and Key Scan  Samples 
MAX6955  2Wire Interfaced, 2.7V to 5.5V LED Display Driver with I/O Expander and Key Scan  Samples 
Next Steps  
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© Jun 25, 2004, Maxim Integrated Products, Inc. 
APP 3210: Jun 25, 2004
APPLICATION NOTE 3210, AN3210, AN 3210, APP3210, Appnote3210, Appnote 3210 