Programming instructions

74xx
 National Instruments Corporation 6-27 Multisim Component Reference Guide
6.4.51 74xx164 (8-bit Parallel-Out Serial Shift Reg)
This 8-bit shift register has gated serial inputs and an asynchronous clear.
Shift register truth table:
6.4.52 74xx165 (Parallel-load 8-bit Shift Reg)
This serial shift-register shifts the data in the direction of QA toward QH when clocked. To
load the data at the 8-inputs into the device, apply a low level at the shift/load input. This
register is equipped with a complementary output at the eighth bit.
Shift register truth table:
INPUTS
INTERNAL
O/P OUTPUTS
SHIFT/
LOAD
CLK INH CLK SERIAL
PARALLEL
A B C D
QA
QB QH
0 X XX abcdabh
1 0 0X XXXXQA0QB0QH0
1 0 · 1 XXXX1 QAnQGn
1 0 · 0 XXXX0 QAnQGn
1 1 XX XXXXQA0QB0QH0
· = transition from low to high
a,b,c,d = the level of steady state input at A, B, C, or D respectively
ComponentRef.book Page 27 Thursday, December 7, 2006 10:12 AM