Page 194 - DCAP108_DIGITAL_CIRCUITS_AND_LOGIC_DESIGNS
P. 194
Unit 11: Registers and Counters
In the table below, we can see how the four-bit binary number 1001 is shifted to the Q outputs Notes
of the register.
Table 11.3: Four-Bit Binary Number 1001 is Shifted to the Q Outputs of the Register
Clear FF0 FF1 FF2 FF3
1001 0 0 0 0
1 0 0 0
0 1 0 0
0 0 1 0
1 0 0 1
An 8-Bit Serial-In/Parallel-Out Shift Register (74hc164)
The 74HC164 is an example of an IC shift register having serial-in/parallel-out operation. The
logic diagram and logic block are shown in Figure 11.8 (a), (b).
Figure 11.8: The Logic Diagram and Logic Block of 74HC164
(9)
CLR
(8)
CLK
(1)
Serial A R R R R R R R R
inputs B (2)
C C C C C C C C
S S S S S S S S
(3) (4) (5) (6) (10) (11) (12) (13)
Q 0 Q 1 Q 2 Q 3 Q 4 Q 5 Q 6 Q 7
a
() Logic diagram
(1)
A SRG 8
(2)
B
(9)
CLR
CLK (8) C
(3) (4) (5) (6) (10) (11) (12) (13)
Q 0 Q Q 2 Q Q Q Q Q 7
4
6
5
3
1
b
() Logic symbol
LOVELY PROFESSIONAL UNIVERSITY 189
