Hi guys,

May i ask for pointers regarding this?

Below is a code that shows setting the TIMER B module to generate two different timing intervals from two control registersim setting the clock at 8MHZ. The first interrupt service routine TIMER B0 outputs 1ms toggling rate and the second interrupt service routine TIMER B1 outputs 10ms toggling rate. But when i test this code, the TIMER B1 does not output 10ms... Im not sure what is really the problem, i suspect the problem is in the setting of CCIE bits. Can you help me figuring what really is the problem in the code below why it does not result in the way i want it? im using MSP430F2274 uCon.

im not quite sure if the timerB module can set different timing...

thanks a lot,

claro

#include "msp430x22x4.h"
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1DIR |= 0x03; // P1.0 output

BCSCTL1 = CALBC1_8MHZ;
DCOCTL = CALDCO_8MHZ;
TBCCTL0 = CCIE; // TBCCR0 interrupt enabled
TBCCTL1 = CCIE;
TBCCR0 = 4000;
TBCCR1 @000;
TBCTL = TBSSEL_2 + MC_2 + ID_1; // SMCLK, contmode

__bis_SR_register(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}
// Timer B0 interrupt service routine showing 1ms toggling
#pragma vector=TIMERB0_VECTOR
__interrupt void Timer_B (void)
{
P1OUT ^= 0x01; // Toggle P1.0
TBCCR0 += 4000; // Add Offset to TBCCR0
}
// Timer B1 interrupt service routine shoeing 10ms toggling rate
#pragma vector=TIMERB1_VECTOR
__interrupt void Timer_B1 (void)
{
P1OUT ^= 0x02; // Toggle P1.0
TBCCR1 += 40000; // Add Offset to TBCCR1
}

---------------------------------
Looking for last minute shopping deals? Find them fast with Yahoo! Search. Start a New Thread

Well, your whole approach is wrong.

1) You are using hardware to set a precise timing, but then use
software to make the pins toggle. Either you use the OUTPUT_TOGGLE
mode for hardware-changing pins TB0 and TB1, obtaining a more precise
timing, or you should use only TIMERB0 in UP_MODE and generate both
signals by software using the same interrupt.

2) TIMERB1_VECTOR shares CC1 throught CC6 interrupt flags, which means
that these are nor being cleared by hardware and you need to do it by
software. I suspect your program is stuck on Timer_B1(), because CCIFG
in TBCCTL1 is never cleared, making P1.2 change at constantly (that
also means you are never again entering Low-power mode after the first
P1.2 toggle) I think the only reason you do see P1.1 change correctly
is that CC0 interrupt has priority over CC1-6.

Best Regards,
Michael Kusch

--- In m..., "old_cow_yellow"
wrote:
>
> TIMERB1_VECTOR is shared with many other interrupts. See User's Guide
> on how to handle it.
>
> --- In m..., Claro Louie wrote:
> >
> > Hi guys,
> >
> > May i ask for pointers regarding this?
> >
> > Below is a code that shows setting the TIMER B module to generate
> two different timing intervals from two control registersim setting
> the clock at 8MHZ. The first interrupt service routine TIMER B0
> outputs 1ms toggling rate and the second interrupt service routine
> TIMER B1 outputs 10ms toggling rate. But when i test this code, the
> TIMER B1 does not output 10ms... Im not sure what is really the
> problem, i suspect the problem is in the setting of CCIE bits. Can you
> help me figuring what really is the problem in the code below why it
> does not result in the way i want it? im using MSP430F2274 uCon.
> >
> > im not quite sure if the timerB module can set different timing...
> >
> > thanks a lot,
> >
> > claro
> >
> > #include "msp430x22x4.h"
> > void main(void)
> > {
> > WDTCTL = WDTPW + WDTHOLD; // Stop WDT
> > P1DIR |= 0x03; // P1.0 output
> >
> > BCSCTL1 = CALBC1_8MHZ;
> > DCOCTL = CALDCO_8MHZ;
> > TBCCTL0 = CCIE; // TBCCR0 interrupt
enabled
> > TBCCTL1 = CCIE;
> > TBCCR0 = 4000;
> > TBCCR1 @000;
> > TBCTL = TBSSEL_2 + MC_2 + ID_1; // SMCLK, contmode
> >
> > __bis_SR_register(LPM0_bits + GIE); // Enter LPM0 w/
interrupt
> > }
> > // Timer B0 interrupt service routine showing 1ms toggling
> > #pragma vector=TIMERB0_VECTOR
> > __interrupt void Timer_B (void)
> > {
> > P1OUT ^= 0x01; // Toggle P1.0
> > TBCCR0 += 4000; // Add Offset to TBCCR0
> > }
> > // Timer B1 interrupt service routine shoeing 10ms toggling rate
> > #pragma vector=TIMERB1_VECTOR
> > __interrupt void Timer_B1 (void)
> > {
> > P1OUT ^= 0x02; // Toggle P1.0
> > TBCCR1 += 40000; // Add Offset to TBCCR1
> > }
> >
> >
> >
> > ---------------------------------
> > Looking for last minute shopping deals? Find them fast with Yahoo!
> Search.
> >
> >
> Start a New Thread