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Calibrating SYSBIOS Timer/Clock

Ram R
Intellectual 420 points
Other Parts Discussed in Thread: SYSBIOS

Hello BIOS experts,

Here is my setup:

  • CCS:  Version: 4.2.4.00033
  • bios_6_32_02_39
  • xdctools_3_22_01_21

I am porting some platform-agnostic framework/C-code from a C6472 platform to a C6424 platform and am seeing some problems... I have pared it down to a simple example - attached cfg and source file.

I am running these examples on  the simulator and using the default RTSC platforms:

  • ti.platforms.evm6472 (default speed = 700 MHz)
  • ti.platforms.evm6424 (default speed = 594 MHz)

Given that the default tick is 1000us = 1 ms, the C6472 sim counts ~ 700k clocks, which is to be expected.

But, is the timer on C6424 running/updating @ ~ 1/2 clock rate? I did not find anything in the C6424 timer-peripheral spec to indicate that...

Calibrating/measuring timestamps is essential to our design.

Any help is greatly appreciated.

Thanks in advance!

2134.bios_ts.zip

  • 0
    TI__Mastermind 45025 points

    Hi Ram R,

    Ram R said:
    But, is the timer on C6424 running/updating @ ~ 1/2 clock rate? I did not find anything in the C6424 timer-peripheral spec to indicate that...

    Looking at the BIOS file ti/sysbios/timers/timer64/Timer.xs, I see that the 6424's timers are running at 27 MHz.

    The 6472's timers run at a rate that's tied to the cpu frequency:

    (clockRate * 1000000) / 6 -> (700 * 1000000) / 6 = 116.67 MHz

    Steve