Originally Posted by Chris Barron
Chris
SHIFTOUT is an I/O function that toggles an output port with the bitwise contents of a data variable. SHIFTIN does the same thing in the other I/O direction.
What I want to do is set up a 'virtual' 1000 tap shift-register in the PIC's memory and be able to clock data through it. It's basically a digital delay line in memory, commonly used for digital signal processing applications. I need to clock it at a well-defined rate and also be able to read any of the 1000 tap points at any time.
It's quite straightforward in assembler, but I wanted to try to incorporate it into an existing PBP program using PBP's ">>" (shift right) and or "<<" (shift left) instructions instead of using assembler. I was hopng someone would tell me there are secret PBP system variables that capture the bits that are shifted OUT of an array variable so they can be shifted back IN to the next variable in the array. This way, a 63-word array could be set up as the 1000-bit shift-register, and bits could be clocked through the 1000 bits as though it were one long shift-register.
Joe
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