Motorola SN54LS170J, SN74LS170N, SN74LS170D Datasheet

4 x 4 REGISTER FILE OPEN-COLLECTOR

The TTL /MSI SN54 /74LS170 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.

Open-collector outputs make it possible to connect up to 128 outputs in a wired-AND configuration to increase the word capacity up to 512 words. Any number of these devices can be operated in parallel to generate an n-bit length.

The SN54/74LS670 provides a similar function to this device but it features 3-state outputs.

•Simultaneous Read/Write Operation

•Expandable to 512 Words of n-Bits

•Typical Access Time of 20 ns

•Low Leakage Open-Collector Outputs for Expansion

•Typical Power Dissipation of 125 mW

CONNECTION DIAGRAM DIP (TOP VIEW)

VCC			D1		WA		WB		EW		ER		Q1		Q2
	16		15		14		13		12		11		10		9

NOTE:

The Flatpak version has the same pinouts

(Connection Diagram) as the Dual In-Line Package.

	1		2		3		4		5		6		7		8
	D2		D3		D4		RB		RA		Q4		Q3		GND

PIN NAMES		LOADING (Note a)
		HIGH	LOW
	Data Inputs
D1 ± D4		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	1.0 U.L.	0.5	U.L.
Q1 ± Q4	Outputs (Note b)	Open-Collector	5 (2.5)	U.L.

NOTES:

a.1 TTL Unit Load (U.L.) = 40 μA HIGH/1.6 mA LOW.

b.The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74)

b. Temperature Ranges. The Output HIGH drive must be supplied by an external resistor to VCC.

SN54/74LS170

4 x 4 REGISTER FILE OPEN-COLLECTOR

LOW POWER SCHOTTKY

			J SUFFIX
			CERAMIC
			CASE 620-09
16	1
			N SUFFIX
			PLASTIC
16			CASE 648-08
	1
			D SUFFIX
	16		SOIC
			CASE 751B-03
		1

ORDERING INFORMATION

SN54LSXXXJ Ceramic

SN74LSXXXN Plastic

SN74LSXXXD SOIC

LOGIC SYMBOL

				12	15		1		2		3
14				WA EW	D1 D2				D3		D
13				WB							4
5				RA	Q1 Q2 Q3 Q4
4				RB ER
				11	10		9		7		6
				VCC = PIN 16
				GND = PIN 8

FAST AND LS TTL DATA

5-1

		SN54/74LS170
		LOGIC DIAGRAM
		D4		D3		D2		D1
12		3		2		1		15
EW
13
WB
WA 14								WORD
G	D	G	D	G	D	G	D	0
	Q		Q		Q		Q
								WORD
G	D	G	D	G	D	G	D	1
	Q		Q		Q		Q
								WORD
G	D	G	D	G	D	G	D	2
	Q		Q		Q		Q
							WORD
G	D	G	D	G	D	G	D 3
	Q		Q		Q		Q
4
RB

11

ER

5

RA

VCC = PIN 16

6	7	9	10
Q4	Q3	Q2	Q1

GND = PIN 8

= PIN NUMBERS

FAST AND LS TTL DATA

5-2