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d4to1mux.pal
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1991-01-12
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2KB
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51 lines
PAL14L8 PAL DESIGN SPECIFICATION
U1 Bob Metzler 12/30/90
DUAL 4:1 MULTIPLEXER
MYTEST REDMOND,WASHINGTON
A1 B1 C1 D1 X1 NC X2 A2 B2 C2 D2 GND
NC NC Y2 NC NC NC NC NC NC Y1 NC VCC
;pinlist 1 to 24 must start in line 5
;equations go here
/Y1 = /X1*/X2 * /A1
+ /X1* X2 * /B1
+ X1*/X2 * /C1
+ X1* X2 * /D1
/Y2 = /X1*/X2 * /A2
+ /X1* X2 * /B2
+ X1*/X2 * /C2
+ X1* X2 * /D2
; function table vectors go here
FUNCTION TABLE
D1 C1 B1 A1 D2 C2 B2 A2 X2 X1 Y1 Y2
;function table pin list
; INPUTS CONTROL OUTPUTS
; D C B A D C B A X X Y Y
; 1 1 1 1 2 2 2 2 2 1 1 2
---------------------------------------------------------
;check for high outputs
H H H H H H H H L L H H
H H H H H H H H H L H H
H H H H H H H H L H H H
H H H H H H H H H H H H
;check for low outputs on Y1
H H H L H H H H L L L H
H H L H H H H H H L L H
H L H H H H H H L H L H
L H H H H H H H H H L H
;check for low outputs on Y2
H H H H H H H L L L H L
H H H H H H L H H L H L
H H H H H L H H L H H L
H H H H L H H H H H H L
---------------------------------------------------------
DESCRIPTION
This example uses a PAL14L8 as a dual 4:1 multiplexer. The select lines
(X1,X2) along with one of the 4 inputs (A,B,C,D) will drive the output
(Y) low. If no inputs are low the outputs are high.