Re: Acess ARM9 hardware timers ( C and Linux )

On 11 Apr, 05:00, "JimNorton" <jimnor...@xxxxxxxxxxxxx> wrote:
Hi Jack,

My processor is a Samsung S3C2410A. Datasheet is here:http://www.datasheetcatalog.org/datasheet2/e/0lrp9fdj0zyd6e2k2e8ej8lk...

I just want to use a timer to time the reading and writing of some GPIO
pins to access some hardware that require uS timing...


Getting uS timing for a Linux application on ARM9 will be tricky.
Linux is not a real-time OS, so it will be difficult for you to ensure
that your I/O-pin-manipulating process is scheduled during the correct
uS. What if an interrupt handler takes over the CPU just when you wish
to toggle the I/O line? Even ignoring Linux, the CPU can give you a
few surprises - a cache miss at the wrong moment might be enough to
mess your timing up.

Since you know PICs and assembly programming, the easiest solution
might be to add a little 8-bitter that handles the timing-critical I/
O, connected to the ARM9 via a serial link (uart, I2C, SPI). Or can
the ARM9's timers be used to generate the desired waveform, without SW
intervention?
.