excamera, what I'm hacking on, daily.

jamesb@excamera.com

CPU improved
OK, I made some improvements to the CPU and it's now running a 3-stage clock - ping is better:

64 bytes from 192.168.0.199: icmp_seq=292 ttl=64 time=7.907 ms

I moved the call-return stack from main memory into a dedicated 16x10 bit RAM. This used 10 additional slices, but then I saved about 10 slices by having a simpler memory interface and sequencer, so it's a wash. Also, this frees up 16 program words.

*

Faster?
OK, I can ping things, but it's a little slow: about 10ms.

64 bytes from 192.168.0.199: icmp_seq=3260 ttl=64 time=10.468 ms
64 bytes from 192.168.0.199: icmp_seq=3261 ttl=64 time=10.469 ms
64 bytes from 192.168.0.199: icmp_seq=3262 ttl=64 time=10.486 ms

The Rabbit on the network is much faster, about 2ms. I think that the current 4 MIPS VHDL CPU needs improvement. (I'm using a 16MHz oscillator, and a very simple 4 cycles/instruction scheme.)

*