SN54LS670 Datasheet, PDF (1/6 Pages) Motorola, Inc – 4 x 4 REGISTER FILE WITH 3-STATE OUTPUTS

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.
• Simultaneous Read/ Write Operation
• Expandable to 512 Words by n-Bits
• Typical Access Time to 20 ns
• 3-State 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
56
78
D2 D3 D4 RB RA Q4 Q3 GND
PIN NAMES
LOADING (Note a)
HIGH
LOW
D1 – D4
WA, WB
EW
RA, RB
ER
Q1 – Q4
Data Inputs
Write Address Inputs
Write Enable (Active LOW) Input
Read Address Inputs
Read Enable (Active LOW) Input
Outputs (Note b)
0.5 U.L.
0.5 U.L.
1.0 U.L.
0.5 U.L.
1.5 U.L.
65 (25) U.L.
0.25 U.L.
0.25 U.L.
0.5 U.L.
0.25 U.L.
0.75 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
16
1
16
1
16
1
J SUFFIX
CERAMIC
CASE 620-09
N SUFFIX
PLASTIC
CASE 648-08
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
SN54LSXXXJ
SN74LSXXXN
SN74LSXXXD
Ceramic
Plastic
SOIC
LOGIC SYMBOL
12 15 1 2 3
14
WA ^{EW D1 D2 D3 D4}
13
WB
5
RA
4
RB _{ER Q1 Q2 Q3 Q4}
11 10 9 7 6
VCC = PIN 16
GND = PIN 8
FAST AND LS TTL DATA
5-597