PIC - driving a shift register in C

Hello people,

got a question for one of my projects. I'm using the PIC18F87J11 for a project and i need to make a shift register. I'll use 3 "normal" I/O lines for creating one. First line for data, second for a clock and third for enable. The lines are directly connected to a CPLD (simplified FPGA), which implemeted a shift register an that part is already working.

Now i'll have to write code in C (beacause my hole project is in C) to create those 3 lines which will drive the shift register (in the CPLD).

I can create clock signals by setting the output high, wait for a while, setting the output low and soo on. But is there a smarter way to do it?

And how can i create a 8 bit serial bit stream? maybe with some shift left/right instructions?

Please help me by solving this problem. Thank You !

here is the sample where 74595 is used (shift register with latched output)


If you use "unlatched" shift registers, then you do not need S_STORE line nor STORE define as all changes are immediate

thank you! works great!

robz said:

thank you! works great!

Click to expand...

ya its very helpful for me!

i m going use 100 shift register for 1200 7segmet connections.
so is it shiftregisters(74hc595) working properly????????
help me frendzx!!!

100 shift registers?? You mean 100 seven segment displays? For what purpose..

I have a simple 8 shift register hook up to a pic16f877a! Using 74ls323 shift registers... But the code ois interrupt driven..