the TC signal is derived by decoding the flip-flop states,

there exists the possibility of decoding spikes on TC. For this

reason the use of TC as a clock signal is not recommended

(see logic equations below).

1.

Count Enable = CEP

•CET • PE

2.

Up: TC = Q

3.

Down: TC = Q

Mode Select Table

PE

CEP

CET

U/D

Action on Rising

Clock Edge

L

X

X

X

Load (P

H

L

L

H

Count Up (Increment)

H

L

L

L

Count Down (Decrement)

H

H

X

X

No Change (Hold)

H

X

H

X

No Change (Hold)

H = HIGH Voltage Level

L = LOW Voltage Level

X = Immaterial

State Diagrams

DS100276-6

3

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