5-597

FAST AND LS TTL DATA

4 x 4 REGISTER FILE

WITH 3-STATE OUTPUTS

The TTL / MSI SN54 / 74LS670 is a high-speed, low-power 4 x 4 Register

File organized as four words by four bits. Separate read and write inputs, both

address and enable, allow simultaneous read and write operation.

The 3-state outputs make it possible to connect up to 128 outputs to in-

crease the word capacity up to 512 words. Any number of these devices can

be operated in parallel to generate an n-bit length.

The SN54 / 74LS170 provides a similar function to this device but it features

open-collector outputs.

CONNECTION DIAGRAM DIP (TOP VIEW)

NOTE:

The Flatpak version

has the same pinouts

(Connection Diagram) as

the Dual In-Line Package.

14

13

12

11

10

9

1

2

3

4

5

6

7

16

15

8

VCC

D2

D1

WA WB EW

Q1

ER

Q2

D3

D4

RB

RA

Q4

Q3 GND

PIN NAMES

LOADING (Note a)

HIGH

LOW

D1 – D4

Data Inputs

0.5 U.L.

0.25 U.L.

WA, WB

Write Address Inputs

0.5 U.L.

0.25 U.L.

EW

Write Enable (Active LOW) Input

1.0 U.L.

0.5 U.L.

RA, RB

Read Address Inputs

0.5 U.L.

0.25 U.L.

ER

Read Enable (Active LOW) Input

1.5 U.L.

0.75 U.L.

Q1 – Q4

Outputs (Note b)

65 (25) U.L.

15 (7.5) U.L.

NOTES:

a) 1 TTL Unit Load (U.L.) = 40

µA HIGH/1.6 mA LOW.

b) The Output LOW drive factor is 7.5 U.L. for Military (54) and 15 U.L. for Commercial

(74) Temperature Ranges. The Output HIGH drive factor is 25 U.L. for Military and

65 U.L. for Commercial Temperature Ranges.

SN54/74LS670

4 x 4 REGISTER FILE

WITH 3-STATE OUTPUTS

LOW POWER SCHOTTKY

ORDERING INFORMATION

SN54LSXXXJ

Ceramic

SN74LSXXXN

Plastic

SN74LSXXXD

SOIC

J SUFFIX

CERAMIC

CASE 620-09

N SUFFIX

PLASTIC

CASE 648-08

16

1

16

1

16

1

D SUFFIX

SOIC

CASE 751B-03

LOGIC SYMBOL

VCC = PIN 16

GND = PIN 8

14

13

5

4

12

15 1 2 3

11 10 9 7 6

WA

WB

RA

RB

EW

ER

D1 D2 D3 D4

Q1 Q2 Q3 Q4