COUNTER AT

MAINSIGNAL VALUE

COUNTER AT

PRESIGNAL VALUE

COUNTER AT

ZERO

MAINSIGNAL OUTPUT

PRESIGNAL OUTPUT

ZERO DETECT OUTPUT

MANUAL

RESET

FIGURE 2. AUTOMATIC OR MANUAL OPERATION IN UP MODE

AUTOMATIC

RESET

COUNTER AT

PRESET NUMBER

COUNTER AT

PRESIGNAL VALUE

COUNTER AT

ZERO

MAINSIGNAL OUTPUT

PRESIGNAL OUTPUT

ZERO DETECT OUTPUT

MANUAL

PRESET

FIGURE 3. AUTOMATIC OR MANUAL OPERATION IN DOWN MODE

COUNTER AT

MAINSIGNAL

NUMBER

AUTOMATIC

PRESET

COUNT INPUT

UP/DOWN

DIVIDE CONTROL

COUNT INHIBIT

RESET

INHIBIT

INTERNAL RESET

PRESET ENABLE

INHIBIT

INTERNAL PRESET

MAINSIGNAL, PRESIGNAL,

ZERO DETECT OUTPUT

DATA TRANSFER

INPUT

SCAN CLOCK

INPUT

MSD OUTPUT

LSD +4 OUTPUT

7 SEGMENTS

OUTPUTS

BCD OUTPUTS

STORAGE SELECT

INPUTS

BCD DATA

INPUT

*

FIGURE 4. TIMING DIAGRAM

7055-012703-4