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74F269

8-bit bidirectional binary counter

NXP Semiconductors. 

NXP Semiconductors

74F269

8-bit bidirectional binary counter

6. Functional description

6.1 Function table

Table 3. Function table[1]

Operating modes

Input

CP

U/D

CEP

CET

PE

Dn

Parallel load (Dn to Qn)

↑

X

X

X

I

I

↑

X

X

X

l

h

Count up (increment)

↑

h

I

I

h

X

Count down (decrement) ↑

I

I

I

h

X

Hold (do nothing)

↑

X

h

I

h

X

↑

X

X

h

h

X

[1] H = HIGH voltage level steady state

h = HIGH voltage level one set-up time prior to the LOW-to-HIGH clock transition

L = LOW voltage level steady state

l = LOW voltage level one set-up time prior to the LOW-to-HIGH clock transition

qn = Lower case letters indicate state of referenced output prior to the LOW-to-HIGH clock transition

X = don’t care

↑ = LOW-to-HIGH clock transition

* = The TC is LOW when CET is LOW and the counter is at terminal count

Terminal count up is with all Qn outputs HIGH and terminal count down is with all Qn outputs LOW.

Output

Qn

TC

L

*

H

*

count up

*

count down *

qn

*

qn

H

74F269_5

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 05 — 25 March 2010

© NXP B.V. 2010. All rights reserved.

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