Yes, DSP/BIOS does use a timer for OS purposes. DSP/BIOS uses the timer
to maintain a system "tick", as well as for supporting some benchmarking
services (CPU load, retrieving high or low resolution timings). The
system tick is used to support TSK task sleeping and various "pend"
services that have associated timeouts. It is possible to configure
DSP/BIOS to *not* use any timer at all, and it is possible to configure
DSP/BIOS to use a timer different than the "default" timer (such as
switching from timer 0 to timer 1).
On systems with both an ARM and DSP, oftentimes the timer usage is
constrained. Linux on the ARM is going to use one of the timers, and it
sounds like you want to use another one for your own purposes. I
believe C64+/ARM combos use the "timer64" model, wherein timers can be
split in half to give lower resolution but more independent timers.
DSP/BIOS will support configuring different timer models, but you need
to be aware of the model used by Linux on the ARM. DSP/BIOS does *not*
share a timer with the ARM (although it might be able to share a given
timer in the "split" model where a 64-bit timer is split into two 32-bit
timers).
- Rob
________________________________
From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]
com] On Behalf Of kashin Lin
Sent: Thursday, January 17, 2008 9:01 AM
To: [email protected]
Subject: About DSP/BIOS's timer usage
Hi,
does DSP/BIOS using any timer as a "OS timer" which is
responsible for issue
a interrupt periodically to support DSP/BIOS's time tick to
schedule the multi-tasks on it?
if yes, which timer DSP/BIOS uses? or we can configure it?
the OS on ARM side i use take timer0 as its OS timer,
should DSP/BIOS use the same one
or it should use others?
thanks for any suggestions.
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