NSC 5962-9161101MLA, 5962-9161101MKA, 5962-9161101M3A, 54ACT825FM-MLS Datasheet

54ACT825
8-Bit D Flip-Flop

General Description

The ’ACT825 is an 8-bit buffered register. They have Clock
Enable and Clear features which are ideal for parity bus in­terfacing in high performance microprogramming systems.
Also included are multiple enables that allow multi-use con­trol of the interface. The ’ACT825 has noninverting outputs
and is fully compatible with AMD’s Am29825.

Features

n Outputs source/sink 24 mA
n Inputs and outputs are on opposite sides
n ’ACT825 has TTL-compatible inputs
n Standard Microcircuit Drawing (SMD)

— ’ACT825: 5962-91611

Logic Symbols

Pin Names Description

D

0–D7

Data Inputs

O

0–O7

Data Outputs

OE

1

,OE2,OE3Output Enables

EN

Clock Enable

CLR

Clear

CP Clock Input

FACT™is a trademark ofFairchild Semiconductor.
TRI-STATE

®

is a registered trademark of National Semiconductor Corporation.

DS100254-1

IEEE/IEC

DS100254-3

February 1999

54ACT825 8-Bit D Flip-Flop

© 1999 National Semiconductor Corporation DS100254 www.national.com

Connection Diagrams

Functional Description

The ’ACT825 consists of eight D-type edge-triggered
flip-flops. These devices have TRI-STATE

®

outputs for bus
systems, organized in a broadside pinning. In addition to the
clock and output enable pins, the buffered clock (CP) and
buffered Output Enable (OE) are common to all flip-flops.
The flip-flops will store the state of their individual D inputs
that meet the setup and hold time requirements on the
LOW-to-HIGH CP transition. With OE

1

,OE2and OE3LOW,
the contents of the flip-flops are available at the outputs.
When one of OE

1

,OE2or OE3is HIGH, the outputs go to the

high impedance state.

Operation of the OE input does not affect the state of the
flip-flops. The ’ACT825 has Clear (CLR) and Clock Enable
(EN) pins. These pins are ideal for parity bus interfacing in
high performance systems.

When CLR is LOW and OE is LOW, the outputs are LOW.
When CLR is HIGH, data can be entered into the flip-flops.
When EN is LOW, data on the inputs is transferred to the
outputs on the LOW-to-HIGH clock transition. When EN is
HIGH, the outputs do not change state, regardless of the
data or clock input transitions.

Function Table

Inputs Internal Output Function

OE

CLR EN CP D

n

QO

HXL

N

L L Z High-Z

HXL

N

H H Z High-Z
H L X X X L Z Clear
L L X X X L L Clear
H H H X X NC Z Hold
L H H X X NC NC Hold
HHL

N

L L Z Load
HHL

N

H H Z Load
LHL

N

L L L Load
LHL

N

H H H Load

H=HIGH Voltage Level
L=LOW Voltage Level
X=Immaterial
Z=High Impedance

N

=

LOW-to-HIGH Transition

NC=No Change

Pin Assignment

for DIP and Flatpak

DS100254-2

Pin Assignment for LCC

DS100254-4

www.national.com 2

Logic Diagram

DS100254-5

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

www.national.com3