DM74LS299 Datasheet, PDF (1/6 Pages) Fairchild Semiconductor – 8-Input Universal Shift/Storage Register with

October 1988
Revised March 2000
DM74LS299
8-Input Universal Shift/Storage Register with
Common Parallel I/O Pins
General Description
The DM74LS299 is an 8-bit universal shift/storage register
with 3-STATE outputs. Four modes of operation are possi-
ble: hold (store), shift left, shift right and load data. The par-
allel load inputs and flip-flop outputs are multiplexed to
reduce the total number of package pins. Separate outputs
are provided for flip-flops Q0 and Q7 to allow easy cascad-
ing. A separate active LOW Master Reset is used to reset
the register.
Features
s Common I/O for reduced pin count
s Four operation modes: shift left, shift right, load and
store
s Separate shift right serial input and shift left serial input
for easy cascading
s 3-STATE outputs for bus oriented applications
Ordering Code:
Order Number Package Number
Package Description
DM74LS299WM
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74LS299N
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbol
Connection Diagram
V_CC = Pin 20
GND = Pin 10
Pin Descriptions
Pin
Names
Description
CP
Clock Pulse Input (Active Rising Edge)
D_S0
D_S7
S0, S1
Serial Data Input for Right Shift
Serial Data Input for Left Shift
Mode Select Inputs
MR
Asynchronous Master Reset Input (Active LOW)
OE1, OE2 3-STATE Output Enable Inputs (Active LOW)
I/O0–I/O7 Parallel Data Inputs or 3-STATE Parallel Outputs
Q0–Q7 Serial Outputs
© 2000 Fairchild Semiconductor Corporation DS009827
www.fairchildsemi.com