4-5 Register.ppt

文档介绍：Flip-flops
Chapter4
Register
Registers, formed from a collection of flip-flops, are used to store or manipulate data or both.
Input and output function associated with registers include
Parallel input / Parallel output
Serial input / Serial output
Parallel input / Serial output
Serial input / parallel output
Flip-flops have two stable state, can store binary code.
One flip-flop can only store one binary bit.
D
Q’
Q
C
Di
Qi
Qi’
Store
Read
Clear
RD
Receive
Simple 1-bit register
Shift Register
Serial input / Serial output Shift register
Universal Shift Register
SN74LS194
Parallel input / parallel output
Four Parallel data inputs permit parallel loading of external data.
Two serial input, one for left-shift, and the other for right-shift.
Serial output data are taken from either QA(LSB) or QD(MSB) depending on shift