RTEMS device driver and interrupt

Chris Caudle chris at chriscaudle.org
Thu Apr 11 01:52:40 UTC 2002

Pattara Kiatisevi wrote:
> The idea is that the write() function to this device should block until
> all the music sent has been played. I plan to:

Will write() be called with an entire file, or with a small buffer?
If with a small buffer (or possibly even with an entire file if you want
to play multiple files continuously) if you wait until all the data has
been played, then what plays while you are processing the next data?

Typically audio hardware has a FIFO memory of some kind, you fill the
FIFO memory, and the hardware interrupts you when the FIFO is half
empty.  That gives you time to get the next set of data loaded into the
FIFO before it is completely empty.

-- Chris Caudle

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