[J-core] Pondering j-core kickstarter ideas.

[Christopher Friedt]

On Tue, Apr 26, 2016 at 7:00 PM, Rob Landley <rob at landley.net> wrote:
> No I am talking about a potential asic, I think I didn't understand
> _your_ question. On-chip clocks and timers to do... what? (High accuracy
> measurements?)

Well, that's one use, of course (e.g. cycle or performance counter).
One other example that immediately comes to mind is the systick on
cortex-m. Another example would be periodic timers (countdown timers)
that fire interrupts. On the last stm32 cortex-m device I was playing
with, there were something insane like 8 periodic timers!

> What I was trying to explain is that I don't know how to add more
> on-chip clocks and timers in VHDL, because it's the "how do I add a

It's pretty simple - for the most part it's just a matter of
downsampling the clock signal from the high speed crystal. Usually
those clock signals are programmable with a ratio in order to allow
for a number of different crystal frequencies and downscaling ratios.