[ECOS] Timing considerations

[eibach@gdsys.de]

Hello,

one of the things my eCos application has to do is to serve a serial port. Platform is an Atmel EB40A.

The device connected to the serial port needs answers to its requests within 1 ms to work properly.

My idea was the following:
- use the EB40A hardware driver for the serial port
- poll the driver every 1 ms using the cyg_io_read command (non-blocking)
- polling could be triggered by an alarm
- that would require a clock with a timing faster than 10 ms between ticks (which is the standard)
- so i use CYGNUM_KERNEL_COUNTERS_CLOCK_OVERRIDE_... options to set the ticks to 100 us
- then i can trigger the alarm every 10 ticks

Am I on the right way? Has anybody better ideas?
Could changing the time between ticks cause any problems?

Regards,
Dirk Eibach


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