LPTMR dont work for a delay shorter than 299ms

paljano — Sun, 06 Jul 2014 11:28:22 GMT

Hello Community,

I have some problems with a kinetis mk10d7. I like to go into stopmode and use the interrupt of the LPTMR to wake up the processor. Behind every wake up the processor should send a char over the UART. Everything works nice when I use a timervalue that let the LPTMR generate a interrupt longer as 299ms. I tryed the LPO and the IRCLK as clock for the LPTMR. It will be nice when you can look on my code. I dont know what the problem is. Thx

#include "derivative.h" /* include peripheral declarations */

#include "driver.h"

int main(void)

{

UART_init(115200,9000); // baud rate=115200,UART_clk~9MHz

LPTMR_init(299); // init LPTMR 500ms 437

SMC_PMCTRL &= ~SMC_PMCTRL_STOPM_MASK;

SMC_PMCTRL |= SMC_PMCTRL_STOPM(0);

//Send data

for(;;)

{

enter_stopmode();

while(!(UART0_S1 & UART_S1_TDRE_MASK)){};

UART0_D = 'a';

}

return 0;

}

#include "derivative.h"

//Device inits

void UART_init(unsigned short baud,unsigned int uartclk_khz)

{

unsigned short sbr,brfa;

//Initialisation

SIM_SCGC4 |= SIM_SCGC4_UART0_MASK;

SIM_SCGC5 |= SIM_SCGC5_PORTB_MASK; // Activate clock for PortC

PORTB_PCR16 = PORT_PCR_MUX(3); // Set PortB 16 for UARC

PORTB_PCR17 = PORT_PCR_MUX(3); // Set PortB 17 for UARC

sbr = (unsigned short)((uartclk_khz*1000)/(baud*16));

UART0_BDH = (unsigned char)((sbr & 0x1F00)>>8); // Write high word of baud rate into register

UART0_BDL = (unsigned char)(sbr & 0x00FF); // Write low word of baud rate into register

brfa = (((uartclk_khz*32000)/(baud*16))-(sbr*32));

UART0_C4 = (unsigned char)(brfa & 0x001F); // Write divider into register

UART0_C1 = 0; // 8-Bit-Mode,No parity

UART0_C2 |= (UART_C2_TE_MASK | UART_C2_RE_MASK ); // Enable receiver and transmitter

}

void LPTMR_init(int timer)

{

SIM_SCGC5 |= SIM_SCGC5_LPTIMER_MASK; // Set clock to LPTMR

LPTMR0_CSR=0x00;

LPTMR0_PSR=0x00;

LPTMR0_CMR=0x00;

MCG_C1|=MCG_C1_IRCLKEN_MASK;

LPTMR0_CMR = timer; // Set counter

LPTMR0_PSR |= LPTMR_PSR_PBYP_MASK // Prescaler is bypassed

| LPTMR_PSR_PCS(1); // Set timer source 0=IRCLK,1=LPO

LPTMR0_CSR |= LPTMR_CSR_TIE_MASK; // Enable interrupt

NVICICPR2 |= (1<<21); //Clear any pending interrupts on LPTMR

NVICISER2 |= (1<<21); //Enable interrupts from LPTMR module

NVICIP85 = 0x10; //Set Priority 3 to the LPTMR module

LPTMR0_CSR |= LPTMR_CSR_TEN_MASK; // activate LPTMR

}

//Enter power modes

void enter_stopmode()

{

volatile unsigned int dummyread;

dummyread = SMC_PMCTRL;

SCB_SCR |= SCB_SCR_SLEEPDEEP_MASK;

asm("WFI");

}

My ISR:

void lptmr_irq(){

LPTMR0_CSR|=LPTMR_CSR_TCF_MASK;

}

Re: LPTMR dont work for a delay shorter than 299ms

kerryzhou — Tue, 08 Jul 2014 09:24:27 GMT

Hi Eric Paljan,

Could you tell me what do you mean LPTMR don't work for a delay shorten than 299ms?

Is your stop mode can't wake up? please give me more details about your question.

Did you test your consumption when you have problem?

By the way, please tell me the full name of your chip.

Waiting for your reply!

Best regards,

Jingjing

Re: LPTMR dont work for a delay shorter than 299ms

paljano — Wed, 09 Jul 2014 06:23:45 GMT

Hello Jingjing,

I´ve solved the problem already. I changed the MCU and anythink was fine. The MCU had a defekt.

Best regards,

Eric

Re: LPTMR dont work for a delay shorter than 299ms

kerryzhou — Wed, 09 Jul 2014 08:39:44 GMT

OK, that's good!

If you still have question, you still can let me know!

Best regards,

Jingjing

topic Re: LPTMR dont work for a delay shorter than 299ms in Kinetis Microcontrollers

LPTMR dont work for a delay shorter than 299ms

Re: LPTMR dont work for a delay shorter than 299ms

Re: LPTMR dont work for a delay shorter than 299ms

Re: LPTMR dont work for a delay shorter than 299ms