GPTIMER Interrupt on CC2538 using Contiki

Paul White95

Hi,

How do I set the ISR function for GPTIMER 1A? Otherwise, does the following look correct?

Thanks,

Paul

void initISR(){
	//set up timer
	REG(GPT_1_BASE + GPTIMER_CTL) = 0; // off
	REG(GPT_1_BASE + GPTIMER_CFG) = 0x04; // 16 bit
	REG(GPT_1_BASE + GPTIMER_TAMR) = GPTIMER_TAMR_TAMR_ONE_SHOT | GPTIMER_TAMR_TAMIE;
	REG(GPT_1_BASE + GPTIMER_TAPR) = 1;
	REG(GPT_1_BASE + GPTIMER_TAILR) = 1000;
	REG(GPT_1_BASE + GPTIMER_IMR) = GPTIMER_IMR_TATOIM;
	REG(GPT_1_BASE + GPTIMER_CTL) = GPTIMER_CTL_TAEN;
	
	//set up interrupt
	nvic_interrupt_enable(NVIC_INT_GPTIMER_1A);
	//TODO: set ISR function
}

over 9 years ago

0 YiKai Chen over 9 years ago

Guru 735685 points

Try to refer to GPTimer example in CC2538 foundation firmware.

0 Paul White95 over 9 years ago in reply to YiKai Chen

Prodigy 120 points

Thanks. That helped. Also needed to replace default_handler with ISR function in startup-gcc.c

This is the working code that initialized the interrupt

void initISR(){
	//set up timer
	REG(SYS_CTRL_RCGCGPT) |= SYS_CTRL_RCGCGPT_GPT1; // enable GPT 1
	REG(GPT_1_BASE + GPTIMER_CTL) = 0; // off
	REG(GPT_1_BASE + GPTIMER_CFG) = 0x04; // 16 bit
	REG(GPT_1_BASE + GPTIMER_TAMR) = GPTIMER_TAMR_TAMR_PERIODIC | GPTIMER_TAMR_TAMIE;
	REG(GPT_1_BASE + GPTIMER_TAPR) = 1;
	REG(GPT_1_BASE + GPTIMER_TAILR) = 480; // 15us at 32MHz
	REG(GPT_1_BASE + GPTIMER_IMR) = GPTIMER_IMR_TATOIM;
	REG(GPT_1_BASE + GPTIMER_CTL) = GPTIMER_CTL_TAEN;

	//set up interrupt
	nvic_interrupt_enable(NVIC_INT_GPTIMER_1A);
}

0 YiKai Chen over 9 years ago in reply to Paul White95

Guru 735685 points

You are welcome and it's good to know it works now.

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GPTIMER Interrupt on CC2538 using Contiki