Position: Index > Amplifier Circuit >

the expansion circuit of a 8-bits parallel port of PI port

2015-01-01 06:16  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.


the expansion circuit of a 8-bits parallel port of PI port
If there are toomany expansions and strobe signals take too many bits of parallel ports.For example,if you want to expand 8 parallel output ports.Then you need 8 signals.At this time,just these signals can take 8-bits parallel ports.Such huge resources wasting phenomena in singlechip system with limited I/O port linesare not tolerable.It adopts chip 74HC573( octal transparent type D flip-latch with three state output) to expand p1 port with 8-bits parallel port.Strobe signal adopts P3.3's pin of P3 port. The principle diagram is as seen as above.