MM54HC195/MM74HC195
4-Bit Parallel Shift Register
General Description
The MM54HC195/MM74HC195 is a high speed 4-bit SHIFT
REGISTER utilizes advanced silicon-gate CMOS technology
to achieve the low power consumption and high noise
immunity of standard CMOS integrated circuits, along with
the ability to drive 10 LS-TTL loads at LS type speeds.
This shift register features parallel inputs, parallel outputs, JK
serial inputs, SHIFT/LOAD control input, and a direct
overriding CLEAR. This shift register can operate in two
modes: PARALLEL LOAD; SHIFT from QA towards QD.
Parallel loading is accomplished by applying the four bits of
data, and taking the SHIFT/LOAD control input low. The
data is loaded into the associated flip flops and appears at
the outputs after the positive transition of the clock input.
During parallel loading, serial data flow is inhibited. Serial
shifting occurs synchronously when the SHIFT/LOAD control
input is high. Serial data for this mode is entered at the
J-K inputs. These inputs allow the first stage to perform as a
J-K or TOGGLE flip flop as shown in the truth table.
The 54HC/74HC logic family is functionally as well as pinout
compatible with the standard 54LS/74LS logic family.
All inputs are protected from damage due to static discharge
by internal diode clamps to VCC and ground.