Flow Control - Making an 8 Bit pipelined CPU - Part 54
James Sharman
This video is a massive step forward for the functionality of the processor even though not much is added to the circuit. The main change is adding a 5way dupont cable connecting the ALU's flags to spare control inputs on the pipeline. This allows the addition of instructions where the behaviour is changed by the flags, the most important of these is flow control instructions, i.e. conditional jumps.
For the functionality demo at the end, jump here: https://www.youtube.com/watch?v=5IPoQtr8xZA&t=2099
There is some troubleshooting, I discover some behaviour from the counter chips I hadn't accounted for, I work around that a change in the assembler but I'll probably come back to that later.
I finish by recreating the 16 bit Fibonacci sequence from the ALU demo only this time using loops and an automatic reset to the start on completion.
The x86 JUMP Quick reference page I refer to: http://www.unixwiz.net/techtips/x86-jumps.html ... https://www.youtube.com/watch?v=5IPoQtr8xZA
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