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Problems with Timer1 and 2 of SAB80C535

Andy Sturm

Morning,

I have some stupid troubles with my SAB80C535 µP. I'm trying to read a acceleration sensor (ADXL202JE) with timer 1 and 2. It works aproximatily fine, excepting the "turbulent" resolution, when the timers work separately. But when i put the two timers together in the main programm then all is messed up. The equation is all disturbed and i get astronomical numbers close to ininit or zero. Can it be posible that the timer 1 and 2 cant work together or are there any priority confuses??
Its driving me crazy !!!!!

Thanks for any answer....

Parents Reply Children
  • 0 in reply to erik malund

    Interrupt 10 is for the CC0 unit of timer 2 and is triggered at falling edge. In the main program i first wait for the rising edge and then start the timer and then the interrupt ocurs at the next rising edge. Thats how i messure the pulswidth of one period.

    Interrupt 11 is for the CC1 unit of the timer 2 and is trigered at rising edge and it is used to messure the time of one period.

  • 0 in reply to Andy Sturm

    anyhow, as stated before and now with a specific example
    if T2 interrupts and, one instruction cycle later T1 interrupts, you will get a misread on T1 of something like 40 counts (I can not give anything accurate based on C source). Could that be what you are seing?

    Erik

  • 0 in reply to erik malund

    The first timer that starts is the Timer 1:

            while (test_Y == 0)
        {
                        IE1 = 0;
                        TMOD = TMOD | 0x90;
                        TR1 = 1;
                        EX1 = 1;
        }


    The while statement is there so the program can't change to anouther while statement. It waits till the interrupt of timer1 is over and then goes to the next statement. I dont know if this is the problem. Because even if i put timer 1 first or second it doesn't matter, the reaction is the same. What i am seeing on the Timer 1 register is 0. That meens he doesent start o something like that. How could that be?

  • 0 in reply to Andy Sturm

    Just to see, Y would try

            {
                        IE1 = 0;
                        TMOD = TMOD & 0x0f;
                        TMOD = TMOD | 0x90;
                        TR1 = 1;
                        EX1 = 1;
        }

    Erik