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eCos and PC timer
- From: Rafael Rodríguez Velilla <rrv at tid dot es>
- To: ecos <ecos-discuss at sources dot redhat dot com>
- Date: Thu, 04 Apr 2002 15:21:45 +0200
- Subject: [ECOS] eCos and PC timer
- Organization: Telefónica I+D
I'm not very familiar with the hardware of PCs, but I think that there
is only one timer available for all the system.
I wanted to process a sampled sound from my SoundBlaster in real time,
so the only solution that I found was programming the Sound Blaster to
sample the sound automatically and transfer it to the memory, and using
a peridicall interrupt to process the sounfd and transfer it to the
speakers (I don't know how to program a second DMA buffer to transfer
the processed sound to the output of the Sound blaster).
The problem is that there's only a timer available, and eCos uses it,
so I was going to extend the RTC routines to fit my pourposes while
keeping the functionality that eCos expects from the timer.
My idea is to add a function that allows the user to program the timer
to produce an interrupt after the desired time, this IRQ throws the
programmed handler.
The function should be clever enough to throw the RTC's ISR and DSR
only when necessary.
Is there something similar available in eCos?
Would this improvement be useful for anyone else? (I ask this to make
t work just for me or to try to make it useful for others, contributing
the code)
I would also like to ask if someone knows of a good forum where I
could ask about low level programming for PCs. (Surely I can program the
Sound Blaster to work in full-duplex mode using two DMA buffers, instead
of using one DMA for collecting samples and IRQs to output the sound).
Thank you for your attention.
--
Rafael Rodríguez Velilla rrv@tid.es
Telefónica I+D http://www.tid.es
Telf: +34 - 91 337 4270
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