Compiler/CC2541: Configuring Timer 1 "input capture mode"

Robert John Dichos

Part Number: CC2541

Tool/software: TI C/C++ Compiler

Good Day,

I need to configure P0_7 of CC2541 as input capture mode of Timer1. Need to read the period and duty cycle produced by an external PWM. This is the first time i will try this with simpleBLEpheriperal as base project, i need some confirmations.

Since i will use P0_7 as input capture pin...

- P0SEL = 0x80;//set to peripheral.

then, base on pin mapping of I/O, P0_7 is at "ALT 2", How to set PERCFG.T1CFG to "ALT 2"? "0" or "1"?

I'm planning to read the period and duty cycle produced by the external PWM at my periodic event. is this at T1CNTH and T1CNTL?

What are the things i missed here?

I know this is like asking for a sample code, but right now i am at a lost..

Thanks.

over 8 years ago

0 Robert John Dichos over 8 years ago

Intellectual 650 points

Is this the correct initialization for Timer 1 input capture mode at Port0 pin 7?
T1CTL = 0;
T1CCTL0 = BV(1) | BV(0);
T1CCTL1 = 0;

P0SEL |= BV(7);
T1CTL |= BV(2);
T1CCTL0 |= BV(7);
T1IE = 1;
T1CTL |= BV(4);

...then i will just read the values by periodic event from timer1 registers to get Duty Cycle and period of external signal.
Is this the correct approach?
Thanks.

0 Fredrik K over 8 years ago in reply to Robert John Dichos

TI__Guru** 106705 points

Hi Robert,

The information you are looking for is documented in the CC253x/4x User's Guide, Timer1 chapter.
www.ti.com/lit/pdf/swru191

Regards,
Fredrik

0 Robert John Dichos over 8 years ago in reply to Fredrik K

Intellectual 650 points

Hello,

Yes, I actually always refer to that documentation but i am not sure if i am doing it right.

One more thing, about handling the interrupt. Is it correct to set the HAL_ISR_FUNCTION(halKeyPORT0Isr, T1_VECTOR) at hal_key.c?

Thanks.

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Compiler/CC2541: Configuring Timer 1 "input capture mode"