Computer

Programming ATF22V10 PLD – 7 Segment with Linux

Last Updated or created 2022-09-14

The ATF22V10 is a Programmable Logic Device. This means you can program the logic in the chip.

Internally it looks like a big matrix of connections which you can program to connect/disconnect from certain logic.

It has just a bunch of inputs/outputs

So if we want to have a 7 Segment decoder (you can easily buy a BCD decoder .. but these only work for displaying 0-9 and not 0-9A-F for displaying HEX numbers)

7 Segment display
Binary IN7 Segment decodedDisplays
D C B AA B C D E F G
0 0 0 01 1 1 1 1 1 00
0 0 0 10 1 1 0 0 0 0 1
0 0 1 0 1 1 0 1 1 0 12
0 0 1 11 1 1 1 0 0 13
0 1 0 00 1 1 0 0 1 14
0 1 0 11 0 1 1 0 1 15
0 1 1 0 1 0 1 1 1 1 16
0 1 1 1 1 1 1 0 0 0 0 7
1 0 0 01 1 1 1 1 1 18
1 0 0 11 1 1 1 0 1 19
1 0 1 01 1 1 0 1 1 1A
1 0 1 10 0 1 1 1 1 1B
1 1 0 0 1 0 0 1 1 1 0C
1 1 0 10 1 1 1 1 0 1D
1 1 1 01 0 0 1 1 1 1E
1 1 1 11 0 0 0 1 1 1F

Now we see that segment A is 1 in the case of (0,2,3,5,6,7,8,9,A,C,E,F)

When programming the PLD we can write that as: (note / means inverted a plus is OR, and * is AND)
So A is 0 in case of input being (1,4,B,D)

/QA = /D1 * /C1 * /B1 * A1
    + /D1 * C1 * /B1 * /A1
    + D1 * /C1 * B1 * A1
    + D1 * C1 * /B1 * A1

Complete code for galasm

Compiling and burning

GAL22V10
7SEGMENT

Clock   D1   C1   B1   A1    D2   C2    B2    A2    NC  NC   GND
/OE   NC    NC  NC  QG    QF    QE    QD   QC    QB   QA   VCC


/QA =   /D1 * /C1 * /B1 * A1
        + /D1 * C1 * /B1 * /A1
        + D1 * /C1 * B1 * A1
        + D1 * C1 * /B1 * A1

/QB=    /D1 * C1 * /B1 * A1
        + /D1 * C1 * B1 * /A1
        + D1 * /C1 * B1 * A1
        + D1 * C1 * /B1 * /A1
        + D1 * C1 * B1 * /A1
        + D1 * C1 * B1 * A1

/QC =   /D1 * /C1 * B1 * /A1
        + D1 * C1 * /B1 * /A1
        + D1 * C1 * B1 * /A1
        + D1 * C1 * B1 * A1


/QD=      /D1 * /C1* /B1 * A1
        + /D1 * C1 * /B1 * /A1
        + /D1 * C1 * B1 * A1
        + D1 * /C1 * B1 * /A1
        + D1 * C1 * B1 * A1

/QE =     /D1 * /C1 * /B1 * A1
        + /D1 * /C1 * B1 * A1
        + /D1 * C1 * /B1 * /A1
        + /D1 * C1 * /B1 * A1
        + /D1 * C1 * B1 * A1
        + D1 * /C1 * /B1 * A1

/QF =     /D1 * /C1 * /B1 * A1
        + /D1 * /C1 * B1 * /A1
        + /D1 * /C1 * B1 * A1
        + /D1 * C1 * B1 * A1
        + D1 * C1 * /B1 * A1

/QG =     /D1 * /C1 * /B1 * /A1
        + /D1 * /C1 * /B1 * A1
        + /D1 * C1 * B1 * A1
        + D1 * C1 * /B1 * /A1

DESCRIPTION
A 7 segment hex decoder

galasm 7seghex.gal

minipro -p ATF22V10CQZ -w 7seghex.jed

minipro -p ATF22V10CQZ -w 7seghex.jed
Found TL866II+ 04.2.129 (0x281)
Warning: Firmware is newer than expected.
  Expected  04.2.128 (0x280)
  Found     04.2.129 (0x281)

VPP=12V
Warning! JED file doesn't match the selected device!

Declared fuse checksum: 0x98D5 Calculated: 0x98D5 ... OK
Declared file checksum: 0x40B3 Calculated: 0x41A8 ... Mismatch!
JED file parsed OK

Use -P to skip write protect

Erasing... 0.33Sec OK
Writing jedec file...  5.01Sec  OK
Reading device...  0.32Sec  OK
Writing lock bit... 0.35Sec OK
Verification failed at address 0x16C6: File=0x01, Device=0x00 < ------------------ Gives error, but burning seems okay

henri@zspot:~/projects/galasm$ minipro -p ATF22V10CQZ -r 7seghex.out
Found TL866II+ 04.2.129 (0x281)
Warning: Firmware is newer than expected.
  Expected  04.2.128 (0x280)
  Found     04.2.129 (0x281)
Reading device...  0.32Sec  OK

Gives all zeros as output, but device works!
DIP switches are 1100 -> C