Programming instructions

74xx
 National Instruments Corporation 6-87 Multisim Component Reference Guide
6.4.15274xx78 (Dual JK FF (pre, com clk & clr))
The 7478 contains two negative-edge triggered flip-flops with individual JK, individual
preset, common clock and common clear inputs.
JK flip-flop truth table:
PRESET CLEAR J K CLOCK Q Q
0 1 XXX 10
1 0 XXX 01
0 0 X X X 1* 1* (unstable)
1 1 0 0 Ø (no change)
1 1 01Ø 01
1 1 10Ø 10
1 1 1 1 Ø (toggle)
1 1 X X 1 (no change)
* = This configuration will not persist when preset and clear are inactive.
Ø = Transition from high to low.
ComponentRef.book Page 87 Thursday, December 7, 2006 10:12 AM