Page 327 - Mechatronics with Experiments

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JWST499-c05
JWST499-Cetinkunt
ELECTRONIC COMPONENTS FOR MECHATRONIC SYSTEMS 313
D Q D E/CLK Q Q
0 0 No change
0 1 0 1
1 0 No change
E/CLK Q 1 1 1 0
D Flip-flop

S Q S R Q Q
0 0 No change
1 0 1 0
0 1 0 1
R Q 1 1 Not allowed
RS Flip-flop

J Q J K CLK Q Q
0 0 No change
CLK 1 0 1 0
0 1 0 1
K Q 1 1 Toggle
JK Flip-flop
FIGURE 5.46: Flip-flops: D-type, RS-type, JK-type.

D n-1 Q n-1
D Q
E Q

D Q
n-2 n-2
D Q
E Q

D n-3 Q n-3
D Q

E Q

.
. FIGURE 5.47: n-bit data latch buffer using n-set of
. D-type flip-flops for data input and output between
D 0 Q 0 a digital computer bus and I/O devices. Data is
D Q … D ), and then the
placed in the data bus (D 0 n−1
E-line is pulsed to latch the data in the D-flip flops.
E Q After that, the changes in the data bus do not affect
E the output of the D-flip flops (latched data) until a
new pulse in the E-line.