文档介绍：Synchronous Sequential Circuit
Chapter 5
Overview
Universal model
System output Variables
O0
Om
Er
Excitation Variables
E0
Combinational logic
System Input Variables
I0
In
S0
Sx
State Variables
Memory
Flip-flops
CLOCK
Basic concept
Synchronous sequential circuit memory, usually consisting of flip-flops, update circuit states information.
All flip-flops share mon clock pulse input.
The clock input is not a binary value representing the time of day, but rather a ”synchronous” train of pulses. Synchronous memory changes its data only at certain time intervals .
The flip-flops can change state only on a clock pulse edge.
The output of memory (flip-flops) defines the state of a sequential machine. It implies that the state variables are the flip-flop outputs. The next-state equation is the characteristics equation of the flip-flops used in circuit.
Excitation variables are input to memory (flip-flops). When flip-flops are used for the system memory, the excitation variables are the inputs (J-K, R-S, D, T) to the flip-flops. Excitation variables are generated by the binational logic operating on the state variables and input variables.
Basic concept
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