using usci in port isr

berker ışık

Hi everyone;

my program don't enter PORT1_VECTOR ISR second time. It enter first time,but don't enter secondly unless reset the msp430.

* My project, reading RTC & send through UART using ISR

* I use button on P1.4 for enter ISR

* In ISR, i read second via USCI (SPI) & send via USCI(UART) , after read and send minute, it is easy.

my program

#include <msp430.h>
#include "pcf2123_reg.h"

unsigned short i;
unsigned short j;
unsigned char sec ;
unsigned char hour ;

void ClockConfig()
{

BCSCTL1 = CALBC1_8MHZ;
DCOCTL = CALDCO_8MHZ;
BCSCTL2= DIVS_3 + DIVM_0;
BCSCTL3 |= LFXT1S_2;
//MCLK =DCO
//SMCLK=DCO/8

}

void PinConfig()
{

P1SEL = BIT1+BIT2+ BIT5 + BIT6 + BIT7;
P1SEL2 = BIT1+BIT2+ BIT5 + BIT6 + BIT7;

P1DIR |= BIT0+BIT3;
P1OUT |= BIT0+BIT3+BIT4;

P1IE |= BIT4;                             // P1.4 interrupt enabled
P1IES |= BIT4;                            // P1.4 Hi/lo edge
P1REN |= BIT4;                            // P1.4 pullup

P1IFG &= ~BIT4;                           // P1.4 IFG cleared

}

void UartConfig(){

   UCA0CTL1 = UCSSEL_2;
   UCA0BR0 = 104;
   UCA0BR1 = 0;
   UCA0MCTL = UCBRS0;
   UCA0CTL1 &= ~UCSWRST;

}

void SpiConfig()
{
//USCI initialization and configuration

UCB0CTL1 = UCSWRST;

UCB0CTL0 |= UCMST + UCMODE_0 + UCSYNC + UCMSB + UCCKPH ;
UCB0CTL1 |= UCSSEL_2;
//Master,3 pin SPI,Senkron,MSB first,..,..
//Source:SMCLK

UCB0BR0 = 4;
UCB0BR1 = 0;
//Bit Rate

//UCB0MCTL = 0;
//SPI modda modülasyon kullanılmaz

UCB0CTL1 &= ~UCSWRST;
//USCI modül RX ve TX'e hazır
}

int main(void) {
    WDTCTL = WDTPW | WDTHOLD;
    ClockConfig();
    PinConfig();
    SpiConfig();
    UartConfig();

   _BIS_SR(LPM4_bits + GIE);

}

// Port 1 interrupt service routine
#pragma vector=PORT1_VECTOR
__interrupt void Port_1(void)
{

   read_rtc(cmd_rd_seconds,&sec);
    UCA0TXBUF = bcd_to_dec(sec) + 80 ;
    while(!(IFG2 & UCA0TXIFG));

read_rtc(cmd_rd_minutes,&hour);
   UCA0TXBUF = bcd_to_dec(hour) + 80 ;
    while(!(IFG2 & UCA0TXIFG));

   P1OUT ^= 0x01;

   P1IFG &= ~BIT4;
   P1IFG = 0;

}

over 9 years ago

0 Tony Philipsson over 9 years ago

Guru 12050 points

Avoid subcalls to functions inside a IRQ.
You are doing read_rtc() and who knows what that does.

Avoid using while() inside a IRQ.
Irq's need to be Short and Sweet™

How can anything be done then?
Start up main by doing a clear lpm4 bits on exit.
if you have many handlers in main, set a flag and let main sort it out.

I'm doing this and I have 7 different task going at the same time on 2553,
all multitasking as no task is allowed to use while()

0 berker ışık over 9 years ago in reply to Tony Philipsson

Prodigy 85 points

Thank you Tony,

1)While() inside the IRQ vector, is it related my problem?

2)I will post tomorrow detailed code

I have 2 USCI(as SPI,UART). Both clock source SMCLK. When occur IRQ, i use these respectively. When exit IRQ;
P1IFG &= ~BIT4;
P1IFG = 0;

I debug project and IFG really clear then go LPM sleep. But it is anormal?? Next press button it will not generate IRQ.

0 berker ışık over 9 years ago in reply to berker ışık

Prodigy 85 points

The problem solved, but i dont understand still.

When exit IRQ , pin P1.4(irq sensitive pin) value was '0', i changed it while exit '1' . The codes works.

**Attention** This is a public forum

MSP low-power microcontrollers

MSP low-power microcontroller forum

using usci in port isr