RTOS/AM3359: HW dependent BIOS clock configuration

Christoph Obrecht

Part Number: AM3359

Tool/software: TI-RTOS

I'm no solution for following issue.

We have change the cpu oscillator frequency during a product lifetime. (CAN sampling issue...) ans the same software should run at both hardware version.

The PLL setup isn't a problem. The bootloader recognize the oscillator Placement with bootstrap (SYSBOOT) configuration (24MHz or 25MHz) and setup the PLL register. All fine!

The problem is the internal bios clock. The configuration is static defined in the cfg file

ti_sysbios_timers_dmtimer_Timer.intFreq.lo = 24000000;  // or = 25000000

Is there an solution for configure the bios timer at runtime depend on the bootstrap, like the bootloader code?

Or use a other (not oscillator) clock for bios timer?

CCS8, SYS/BIOS 6.52.0.12,

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

The RTOS team have been notified. They will respond here.

0 Christoph Obrecht over 7 years ago

Prodigy 220 points

Part Number: AM3359

Tool/software: TI-RTOS

The issue is always open.

Can everybody helps me.

Can I change the Bios clock at runtime?

0 Lalindra Jayatilleke over 7 years ago in reply to Christoph Obrecht

TI__Mastermind 30365 points

Christoph,

I think it would be possible with the use of BIOS_setCpuFreq().
I have looped in the RTOS experts to comment on the exact changes needed to make this happen if its available.

Lali

0 Darius Williams over 7 years ago in reply to Lalindra Jayatilleke

TI__Expert 4440 points

Christoph,

I think Lali's suggestion is worth a try.

See here for further documentation.

Derrick

0 Christoph Obrecht over 7 years ago in reply to Darius Williams

Prodigy 220 points

In my point of view is, that this function BIOS_setCpuFreq() set the Core/CPU frequency, but this is always correct with the PLL configuration (see in my first post).
The problem is the internal bios tick and this tick is dependent on the oscillator frequency. (at least in my implementation)
I need a function to set the SYS_BIOS_TIMER frequency. Or a possibility to use a oscillator-independent clock for the bios timer.

0 Christoph Obrecht over 7 years ago in reply to Lalindra Jayatilleke

Prodigy 220 points

see post from Jul 25

0 Darius Williams over 7 years ago in reply to Christoph Obrecht

TI__Expert 4440 points

Christoph,

I understand now.

You will need to use the Clock_tickReconfig() function.

/* 
 * Disable interrupts if an interrupt could lead to
 * another call to Clock_tickReconfig() or if interrupt
 * processing relies on having a running timer
 */

/* Hwi_disable() or Swi_disable() */
BIOS_setCpuFreq(&freq);
Clock_tickStop();
Clock_tickReconfig();
Clock_tickStart();
/* Hwi_restore() or Swi_enable() */


/* 
 * If calling Clock_tickReconfig() before BIOS_start(), the timer has not yet been started.
 * As a result, you can use the following simplified call sequence in main():
 * The return value is false if the timer cannot support the new frequency
 */
BIOS_setCpuFrequency(Types.FreqHz *freq);
ret = Clock_tickReconfig(Void);

See here for more details.

Derrick

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RTOS/AM3359: HW dependent BIOS clock configuration