Programming instructions

74xx
 National Instruments Corporation 6-11 Multisim Component Reference Guide
6.4.20 74xx12 (Tri 3-In NAND (OC))
This device contains three independent 3-input NAND gates. For correct performance, the
open collector outputs require pull-up resistors.
Logic function:
NAND gate truth table:
6.4.21 74xx125 (Quad bus BUFFER w/3-state Out)
This device contains four independent BUFFER/non-inverting gates with 3-state outputs.
BUFFER gate truth table:
The output of the bus buffer is disabled when G is high.
Y = ABC
ABCY
0001
1001
0101
1101
0011
1011
0111
1110
A GY
100
001
X1Z
Z = high impedance
ComponentRef.book Page 11 Thursday, December 7, 2006 10:12 AM