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System clock requirement

A project log for rhombus

An open-source minimalist 68020 based single board computer

Jason WesterveltJason Westervelt 12/27/2015 at 02:002 Comments

In preparation for eventually booting uClinux (and full linux once I get my MMU and dynamic ram controller built), I'll need a system clock of sorts. I'm not too terribly familiar with how linux deals with the system clock/timer, but I am guessing that an interrupt would need to be triggered every so often... 1khz? 100hz? Anyone know the juicy details on what is needed from both a hardware and a configuration aspect?

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Jason Westervelt wrote 12/27/2015 at 06:39 point

Thanks, it gives me a bit of direction.  I was originally thinking 1ms, but that may be too much for a 16MHz CPU to deal with.  I'll run with 100Hz/10ms and see what happens.

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K.C. Lee wrote 12/27/2015 at 04:24 point

Not sure, but I found this:

http://uclinux-dev.uclinux.narkive.com/s1rwXkRW/uclinux-2-4-x-68328
>Anyway, my system still have problems when tries to create a first INIT kernel_thread. I use 68000 processor with timer (10 ms tick, jiffies=76), uart 115200. It is quite similar to 68328 platform.

Based on what I know of porting ChibiOS (ARM Cortex), you find the closest supported hardware platform and try to modify the code (and in this case may be the hardware if it means less work).

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