MSP430F6459: msp430f6459

Aravind koneti

Part Number: MSP430F6459

Hi,

I am writing a simple application where the controller should receive the character through UART interrupt and meanwhile my while loop should run indepedently.

The below is code I am trying to do where UART should accept the character and my while loop should run continuously and should execute the if or else if condition based on the character received.

But it is not working in that way, it is stopping at __bis_SR_register(LPM0_bits + GIE); and not even entering into the while loop.

Can anyone please help me to solve this issue.

void main(void)

{

__bis_SR_register(LPM0_bits + GIE);

while(1)
{
if(UartRx_flag == 1)
{
UartRx_flag = 0;

if(UCA0RXBUF == 0x31)
{
__delay_cycles(100000);
ReadLocalTemp();
TestMenu();
}
else if(UCA0RXBUF == 0x32)
{
__delay_cycles(100000);
ReadRemoteTemp();
TestMenu();
}
}

}

}

//******************************************************************************
// UART RX Interrupt ***********************************************************
//******************************************************************************

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_A0_VECTOR
__interrupt void USCI_A0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_A0_VECTOR))) USCI_A0_ISR (void)
#else
#error Compiler not supported!
#endif
{
switch(__even_in_range(UCA0IV,4))
{
case 0:break; // Vector 0 - no interrupt
case 2: // Vector 2 - RXIFG
while (!(UCA0IFG & UCTXIFG)); // USCI_A0 TX buffer ready?

UCA0TXBUF = UCA0RXBUF; // TX -> RXed character

UartRx_flag = 1; // Making flag high

break;
case 4:break; // Vector 4 - TXIFG
default: break;
}
}

Thanks & Regards,

K. Aravind,

Sigma Advanced Systems,

9848992750.

over 3 years ago

0 Dylan OBrien over 3 years ago

TI__Genius 16050 points

Hi Aravind,

There are two things I want to check about to start solving this issue:

1) I do not see any code to initialize the pins or relevant registers in order to perform UART transfers. Is this included in the code you are executing? If so, you may want to include it in your response so I can see everything you are executing in your program. If not, you should add this code so that the UART module can effectively perform transfers.

2) Can you check and confirm that your ISR is executing?

Thanks

0 Keith Barkley over 3 years ago

Guru 44035 points

Make sure UartRx_Flag is volatile.

0 Aravind koneti over 3 years ago in reply to Dylan OBrien

Prodigy 245 points

Hello Dylan OBrien,

I have initialised everything that required and yes ISR is executing.

My only problem is what is __bis_SR_register(LPM0_bits + GIE)

Thanks,

Aravind.

0 Aravind koneti over 3 years ago in reply to Keith Barkley

Prodigy 245 points

Hello Keith Barkley,

Thanks for the response.

It's is not even entering into the while loop that I wanted to execute but ISR is executing.

The execution is stopping at __bis_SR_register(LPM0_bits + GIE).

What exactly this method used for

Thanks,

Arvind

0 Keith Barkley over 3 years ago in reply to Aravind koneti

Guru 44035 points

It puts it in low power mode after the interrupt, so that the while loop does not even run, only interrupt code. Get rid of the "LPM0_bits"

+1 Dylan OBrien over 3 years ago in reply to Aravind koneti

TI__Genius 16050 points

That line of code enables interrupts globally and puts the device into low power mode 0. As Keith mentioned in his response, you can remove the "LPM0_bits" portion of the line so that the device never enters low power mode.

Please give this a try and let us know if it resolves your issue, or if you need further assistance.

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MSP430F6459: msp430f6459