HD74HC674 Datasheet, PDF (1/8 Pages) Hitachi Semiconductor – 16-bit Shift Register

HD74HC674
16-bit Shift Register
Description
The HD74HC674 is a 16-bit parallel-in, serial-out shift register. A three-state input/output (data I/O) port
provides access for entering serial data or reading the shift-register word in a recirculating loop.
The device has four basic modes of operation:
1. Hold (do nothing)
2. Write (serially via input/output)
3. Read (serially)
4. Load (parallel via data inputs)
Low-to-high-level changes at the chip select input should be made only when the clock input is low to
prevent false clocking.
Features
• High Speed Operation: t_pd (CLK to SER/Q₁₅) = 17 ns typ (C_L = 50 pF)
• High Output Current: Fanout of 15 LSTTL Loads
• Wide Operating Voltage: V_CC = 2 to 6 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: I_CC (static) = 4 µA max (Ta = 25°C)
Function Table
Inputs
CS
R/W
H
X
L
L
L
H
L
H
Mode
X
X
L
H
CLK
X
SER/Q₁₅
Z
Z
Q_14n
P₁₅
Operation
Do nothing
Shift and write (serial load)
Shift and read
Parallel load