1. Code Converters
Section 3-4 Mano & Kime

2. Code Converters BCD-to Excess-3 Code Converter
Hex-to-Seven-Segment Decoder
Lab 3 – ALU2
Arithmetic and Logic Instructions
7-Segment Decoder

3. BCD-to Excess-3 Code Converter

4. Maps for BCD-to-Excess-3 Code Converter

5. Logic Diagram of BCD-to-Excess-3 Code Converter

6. Excess3
inp(3:0)
outp(3:0)

7. Note: inp(3:0) = [A, B, C, D]
outp(3:0) = [W, X, Y, Z]

8. Code Converters BCD-to Excess-3 Code Converter
Hex-to-Seven-Segment Decoder
Lab 3 – ALU2
Arithmetic and Logic Instructions
7-Segment Decoder

9. Hex-to-Seven-Segment Decoder

10. Turning on an LED

11. 7-Segment Display

12. 7-Segment Display a b c d e f g 0 1 1 1 1 1 1 0 1 0 1 1 0 0 0 0

13. 7-Segment Display a b c d e f g 8 1 1 1 1 1 1 1 9 1 1 1 1 0 1 1 A b C d E F

14. Hex-to-Seven-Segment Decoder

15. a b c d e f g
Note: a – g LOW
to turn ON

16. Code Converters BCD-to Excess-3 Code Converter
Hex-to-Seven-Segment Decoder
Lab 3 – ALU2
Arithmetic and Logic Instructions
7-Segment Decoder

17. ALU2 – Arithmetic and Logic Instructions
sel y
Instruction name
“000”
a + b +
“001”
b - a -
“010”
a and b
AND
“011”
a or b OR
“100”
a xor b
XOR
“101”
true if a = 0
false otherwise 0=
“110”
true if a < 0
0<
“111”
true if b > a (unsigned)
U>
true = all 1’s
false = all 0’s

18. Digilab2 – DIO1 Boards
Four 7-segment
displays
dig1
dig2
dig3
dig4

19. Digilab2 Board – Common Anodes
Pins
A1 A2 A3 A4
Pins
AtoG(6 downto 0)

20. Digilab XLA
LEDs
7-segment displays
pushbuttons
switches

21. Digilab Board
dig4
dig3
dig2
dig1

22. Digilab XLA Board – Common Anodes
Pins
A4 A3 A2 A1
Pins
CA CB CC CD CE CF CG

23. Top-level Design – Lab 3 Display y on dig4 ldg Lab3 a(3:0) ALU2
sel(2:0) y
SW(5:8)
A(1:4)
BTN(1:3)
ldg
‘1’
SW(1:4)
b(3:0)
AtoG(6:0)
seg7dec q
AtoG
“0001”
LD(1:8) y1
Display y
on dig4