Philips Semiconductors

Product specification

74ALS646/74ALS646-1

74ALS648/74ALS648-1

Transceiver/register

1991 Feb 08

9

AC WAVEFORMS

The shaded areas indicate when the input is permitted to change for predictable output performance.

CPBA

or

CPAB

VM

VM

VM

tw(H)

1/fmax

VM

VM

tPLH

tw(L)

tPHL

An or Bn

SF00394

Waveform 1.

Propagation Delay for Clock Input to Output,

Clock Pulse Width, and Maximum Clock Frequency

SF00395

Bn or An

An or Bn

SBA or SAB

An or Bn

Waveform 2.

Propagation Delay for An to Bn or Bn to An

and SAB or SBA to An or Bn

VM

VM

VM

VM

tPHL

tPLH

An or Bn

Bn or An

SBA or SAB

An or Bn

SF00396

Waveform 3.

Propagation Delay for An to Bn or Bn to An

and SAB or SBA to An or Bn

VM

VM

VM

VM

VM

VM

tsu(L)

th(L)

tsu(H)

th(H)

An or Bn

CPBA

or

CPAB

SF00397

Waveform 4.

Data Setup Time and Hold Times

VM

VM

VM

tPHZ

tPZH

OE

VOH -0.3V

0V

An or Bn

DIR

SF00398

Waveform 5.

3-State Output Enable Time to High Level

and Output Disable Time from High Level

VM

VM

VM

tPLZ

tPZL

VOL +0.3V

3.5V

OE

DIR

An or Bn

SF00399

Waveform 6.

3-State Output Enable Time to Low Level

and Output Disable Time from Low Level