[ECOS] AT91M40400 Counters

[Carl van Schaik <carl at leg dot uct dot ac dot za>]

Hi

I'm having a bit of a problem with the Atmel EB01 (AT91M40400 CPU) port,
and it is concerned with the timer used for the real-time clock.

Anyone got system level programming experience on this chip?

I have a problem with the interupts on the timer. It seems that in certain
cases, the interupt controller is getting confused and stops recieving
clock interupts. This is most visible in the examples that print a lot of
text (tm_basic).

Setup:
  Clock = 32.768MHz
  Timer clock = 16.384Mhz
  Timer interupt = 250Hz
  CYGNUM_HAL_RTC_NUMERATOR = 100000000
  CYGNUM_HAL_RTC_DENOMINATOR = 250
  CYGNUM_HAL_RTC_PERIOD = 65536

When debugging at 9600 baud, the program execution is correct and no
problems are observed. At 115200 baud, the tests lockup randomly when
performing either thread/clock operations (I don't know which).
My guess it has something to do with the masking/unmasking of interupts.

I have also noticed that I can't get the clock running at high rates
without it locking up, maby that is a related problem.

The AT91M40400 has high speed 32bit wide SRAM at address 0x0, would there
be much code change to relate the exception handlers to that memory after
bootup?

thanks

Carl van Schaik   <carl@leg.uct.ac.za>
-----------------------------------------------------
Dept. Electrical Engineering, UCT

621 Menzies Building
University of Cape Town
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Tel: +27 21 650-3467
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