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PROM Inputs PROM Outputs
"e '7 »e '5 >4 "3 >2 »1 Y Y Y
'9 "o ' 2 ' 1 ' 0
0 0 0 0 0 0 0 0 0 0
• PROM
0
0 0 1 1 1 1 1 1 1 1
0 1 0 0 0 0 0 0 0 0
• PROM 1
0 1 1 1 1 1 1 1 1 1
1 0 0 0 0 0 0 0 0 0
• PROM
2
1 0 1 1 1 1 1 1 1 1
1 1 0 0 0 0 0 0 0 0
• PROM 3
1 1 1 1 1 1 1 1 1 1

FIGURE 7.17
Partitioned PROM program table required to generate three output functions of 10 variables by usin§
8
four 2 x 4 PROMs.

I 9,I 8(H)

/ '2 / 8
V

2-to-4 Decoder
3 2 1 0
u (J (J
L

I !

PR DM PROM 2 PROM., PR(DM 0
3
EN >-c EN L-C EN L-C EN
? I 1 (p 2 1 0 2 1 0 1 0
\ LT M
^

Y 2(H) Y^H) Y 0(H)
FIGURE 7.18
Multiplexed scheme required by the program table of Fig. 7.17 to generate three functions of 10
8
variables by using four 2 x 4 PROMs.

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