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- module bcd7rom flag '-d82'
- title 'seven segment display decoder
- Data I/O Corp Redmond WA 16 Mar 1984'
- " a
- " --- BCD-to-seven-segment decoder similar to the 7449
- " f| g |b
- " --- segment identification
- " e| d |c
- " ---
- " --- --- --- --- --- --- --- ---
- " | | | | | | | | | | | | | |
- " --- --- --- --- --- --- ---
- " | | | | | | | | | | | | |
- " --- --- --- --- --- --- ---
-
- U6 device 'RA5P8';
-
- D3,D2,D1,D0 pin 10,11,12,13;
- a,b,c,d,e,f,g pin 1,2,3,4,5,6,7;
- ena pin 15;
-
- bcd = [D3,D2,D1,D0];
- led = [a,b,c,d,e,f,g];
-
- ON,OFF = 0,1; " for common anode LEDs
- L,H,X,Z = 0,1,.X.,.Z.;
-
- truth_table (bcd -> led)
- " input outputs
- " a b c d e f g
- 0 -> [ ON, ON, ON, ON, ON, ON, OFF];
- 1 -> [OFF, ON, ON, OFF, OFF, OFF, OFF];
- 2 -> [ ON, ON, OFF, ON, ON, OFF, ON];
- 3 -> [ ON, ON, ON, ON, OFF, OFF, ON];
- 4 -> [OFF, ON, ON, OFF, OFF, ON, ON];
- 5 -> [ ON, OFF, ON, ON, OFF, ON, ON];
- 6 -> [ ON, OFF, ON, ON, ON, ON, ON];
- 7 -> [ ON, ON, ON, OFF, OFF, OFF, OFF];
- 8 -> [ ON, ON, ON, ON, ON, ON, ON];
- 9 -> [ ON, ON, ON, ON, OFF, ON, ON];
-
- test_vectors ([ena,bcd] -> led)
- " inputs outputs
- " a b c d e f g
- [L,1] -> [OFF, ON, ON, OFF, OFF, OFF, OFF];
- [L,2] -> [ ON, ON, OFF, ON, ON, OFF, ON];
- [L,3] -> [ ON, ON, ON, ON, OFF, OFF, ON];
- [L,4] -> [OFF, ON, ON, OFF, OFF, ON, ON];
- [L,5] -> [ ON, OFF, ON, ON, OFF, ON, ON];
- [L,6] -> [ ON, OFF, ON, ON, ON, ON, ON];
- [L,7] -> [ ON, ON, ON, OFF, OFF, OFF, OFF];
- [L,8] -> [ ON, ON, ON, ON, ON, ON, ON];
- [L,9] -> [ ON, ON, ON, ON, OFF, ON, ON];
- [L,0] -> [ ON, ON, ON, ON, ON, ON, OFF];
- [H,5] -> [ Z, Z, Z, Z, Z, Z, Z];
- [H,9] -> [ Z, Z, Z, Z, Z, Z, Z];
- [H,0] -> [ Z, Z, Z, Z, Z, Z, Z];
- end bcd7rom
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