SN54ALS299 Datasheet, PDF (1/7 Pages) Texas Instruments – 8-BIT UNIVERSAL SHIFT/STORAGE REGISTERS WITH 3-STATE OUTPUTS

SN54ALS299, SN74ALS299
8-BIT UNIVERSAL SHIFT/STORAGE REGISTERS
WITH 3-STATE OUTPUTS
SDAS220B – DECEMBER 1982 – REVISED DECEMBER 1994
• Multiplexed I/O Ports Provide Improved Bit
Density
• Four Modes of Operation:
– Hold (Store)
– Shift Right
– Shift Left
– Load Data
• Operate With Outputs Enabled or at High
Impedance
• 3-State Outputs Drive Bus Lines Directly
• Can Be Cascaded for n-Bit Word Lengths
• Direct Overriding Clear
• Applications:
– Stacked or Push-Down Registers
– Buffer Storage
– Accumulator Registers
• Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Standard Plastic (N)
and Ceramic (J) 300-mil DIPs
description
These 8-bit universal shift /storage registers
feature multiplexed I/O ports to achieve full 8-bit
data handling in a single 20-pin package. Two
function-select (S0, S1) inputs and two output-
enable (OE1, OE2) inputs can be used to choose
the modes of operation listed in the function table.
SN54ALS299 . . . J PACKAGE
SN74ALS299 . . . DW OR N PACKAGE
(TOP VIEW)
S0 1
OE1 2
OE2 3
G/Q_G 4
E/Q_E 5
C/Q_C 6
A/Q_A 7
Q_A′ 8
CLR 9
GND 10
20 V_CC
19 S1
18 SL
17 Q_H′
16 H/Q_H
15 F/Q_F
14 D/Q_D
13 B/Q_B
12 CLK
11 SR
SN54ALS299 . . . FK PACKAGE
(TOP VIEW)
G/Q_G
E/Q_E
C/Q_C
A/Q_A
Q_A′
3 2 1 20 19
4
18
5
17
6
16
7
15
8
14
9 10 11 12 13
SL
Q_H′
H/Q_H
F/Q_F
D/Q_D
Synchronous parallel loading is accomplished by taking both S0 and S1 high. This places the 3-state outputs
in the high-impedance state and permits data applied on the I/O ports to be clocked into the register. Reading
out of the register can be accomplished while the outputs are enabled in any mode. Clearing occurs
asynchronously when the clear (CLR) input is low. Taking either OE1 or OE2 high disables the outputs, but has
no effect on clearing, shifting, or storing data.
The SN54ALS299 is characterized for operation over the full military temperature range of – 55°C to 125°C. The
SN74ALS299 is characterized for operation from 0°C to 70°C.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright © 1994, Texas Instruments Incorporated
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