Running Speed of SX-28
sunruh
Posts: 11
I am doing some speed calculations on my SX-28.· I am running with an external crystal at a freq of 50 mhz.· The instruction set gives the number of cycles for each instruction.· For instance, the ADD instruction has 1 word, and 1(4) cycles.· Does the 4 relate to the number of crystal cycles?· In other words, it takes 4/50,000,000 seconds to complete?
Stan Unruh
Stan Unruh
Comments
the turbo mode is what you would typically use.· the compatible mode has something to do with the SX and the PIC· (C57) code being compatible (in instruction cycles) for an example if you wrote code for the C57 you could easily port it over to the SX.· the pic ran each instruction in 4 cycles.
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DTQ
"The SX family implements a four-stage pipeline (fetch,
decode, execute, and write back), which results in execution
of one instruction per clock cycle."
In turbo mode it will fetch the next instruction at the same time it is decoding the current one and executing the previous one.
The reason that branching instructions like jumps and subroutine calls take more cycles to execute is that the pipeline is cleared on a jump
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I wonder if this wire is hot...
Post Edited (Electronegativity) : 10/17/2005 10:25:29 PM GMT