8

Test Circuits and Waveforms

FIGURE 1. ’HC192 SYNCHRONOUS DECADE COUNTERS, TYPICAL RESET, PRESET AND COUNT SEQUENCES

MASTER RESET

ASYNCHRONOUS PARALLEL LOAD

PRESET DATA

P0

P1

P2

P3

CLOCK UP

CLOCK DOWN

OUTPUTS

TERMINAL COUNT UP

TERMINAL COUNT DOWN

07

89012

COUNT DOWN

COUNT UP

RESET

10987

PRESET

SEQUENCES:

1. RESET OUTPUTS TO ZERO.

2. LOAD (PRESET) TO BCD SEVEN.

TERMINAL COUNT UP, ZERO,

3. COUNT UP TO EIGHT, NINE,

ONE AND TWO.

4. COUNT DOWN TO ONE, ZERO,

TERMINAL COUNT DOWN, NINE,

EIGHT AND SEVEN.

CD54/74HC192, CD54/74HC193, CD54/74HCT193