Converted Z register into Z bus
Realized there’s no reason to have a Z register at all, X and Y need it since their inputs both come off the shared XY input bus, but with Z every time we load it we immediately then use the […]
Realized there’s no reason to have a Z register at all, X and Y need it since their inputs both come off the shared XY input bus, but with Z every time we load it we immediately then use the […]
Wrote a tool that generates digraphs out of the microcode. Also did a bunch of prep work that had to be done before doing more interrupt work, now have instructions to disable/enable interrupts and can individually set/reset FLAGS bits (instead […]
Finished converting all of the unit tests to seasm. Implemented the basic hardware so that interrupts are able to force a jump to microcode interrupt vectors rather than IR when a fetch/execute next happens. Also moved ECLair into a test […]
Started working at moving the unit tests over to seasm rather than raw binary. At this point most of the 8 bit operand tests are moved over, but the “assembler” doesn’t support 16-bit operands yet so that will be the […]
call/ret are finally done and have passing unit tests! Started work on interrupt logic, but ran into an issue that there are no inputs left on the X/Y mux to get the interrupt vectors in anywhere. For the time being, […]
Added realistic propagation delays to alu4 and finished the RAM delays, fixed a couple timing issues and tests all pass at 25MHz and 33MHz now. Am going to leave the clock at 25MHz for the time being, as that’s the […]
Worked on sub8.ab some more, it now works and passes all its unit tests. Also wrote some extra tests for this, to be more confident in its workingness. Next step will be to finally finish CALL and RETURN. I started […]
Worked on pop16.pc more, it now works and passes all of its unit tests. Am still working on sub8.ab, that one still doesn’t work.
Worked on pop16.pc microcode and sub8.ab microcode a bunch. Didn’t get to a point where either works yet.
Figured out the register flow requirements for pop16.pc, and documented it in a diagram. Next step will be to implement the unit test and microcode for it.