Specification of timer mode in the msp430

Rahul Saha

Other Parts Discussed in Thread: MSP430F5438A

In the driver library for the timer module of the msp430f5438a, there is an initialization function for the timer, namely TIMER_A_initUpMode() (to configure the timer in UP mode).

Why do we also need to specify the mode in the TIMER_A_startCounter() method?

Isn't that already mentioned in the previous function?

over 8 years ago

0 Clemens Ladisch over 8 years ago

Guru 316440 points

The TIMER_A_initUpMode() function starts the timer only if the startTimer field is set.

0 Rahul Saha over 8 years ago in reply to Clemens Ladisch

Prodigy 220 points

Does that mean that after i call TIMER_A_initUpMode() (with startTimer being set to true), i must call TIMER_A_startCounter() ?

0 Clemens Ladisch over 8 years ago in reply to Rahul Saha

Guru 316440 points

No; you need a separate call to start the timer only if you did not set startTimer.

0 Rahul Saha over 8 years ago in reply to Clemens Ladisch

Prodigy 220 points

Oh, thank you!
One more follow up question: there are some overlapping values required, such as timerPeriod for the TIMER_A_initUpModeParam structure's instance and compareValue in the TIMER_A_setCompareValue() function. Are there any fixed guidelines as to which function must be used when?

0 Clemens Ladisch over 8 years ago in reply to Rahul Saha

Guru 316440 points

The TIMER_A_initUpMode() function already initializes CCR0; you do not neet to call TIMER_A_setCompareValue() for CCR0.

0 Rahul Saha over 8 years ago in reply to Clemens Ladisch

Prodigy 220 points

In that case would we ever need TIMER_A_setCompareValue(), or, for that matter, even the compareRegister attribute of the TIMER_A_initCompareModeParam structure?

0 Clemens Ladisch over 8 years ago in reply to Rahul Saha

Guru 316440 points

There are more compare registers than CCR0; and when not in up mode, even CCR0 can be used for normal comparisons.

0 Rahul Saha over 8 years ago in reply to Clemens Ladisch

Prodigy 220 points

Thank you!

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Specification of timer mode in the msp430