4 ms·
Current work is at http://github.com/ams/cadr4 http://github.com/ams/cadr4 And of course .. https://tumbleweed.nu/lm-3 https://tumbleweed.nu/lm-3 .
by amszmidt 1y ago
Current work is at http://github.com/ams/cadr4 http://github.com/ams/cadr4
And of course .. https://tumbleweed.nu/lm-3 https://tumbleweed.nu/lm-3 .
- rjsw 1y agoMaybe try replacing the ALU with one written directly in Verilog, I suspect this will run a lot faster than building it up from 74181+74182 components.
- amszmidt 1y agoFrom what I see -- that is not the case. The current state is _very_ fast in simulation to the point where it is uninteresting (there are other things to figure out) to write something as a behavioral model of the '181/'182. ~100 microcode instructions takes about 0.1 seconds to run.
- rjsw 1y agoI was thinking more of a behavioral model of the whole ALU, just so that the FPGA tools can map it onto a collection of the smaller ALUs built into each slice. What clock speed does your latest design synthesize at?
- therealcamino 1y agoAt the top of the readme it says "There will be no attempt at making this synthesizable (at this time)!".
- rjsw 1y agoThere was already a design of CADR for FPGAs [1] that does synthesize (and boot), I don't know why amszmidt needed to start again from scratch or if his design is a modification of the earlier one. A similar comment applies to lm-3. Maybe it is built on a fork of the previous repo, it is hard to tell. [1] https://github.com/lisper/cpus-caddr https://github.com/lisper/cpus-caddr