I want to use UART communication in my project, but whatever I do I can not get UART RX interrupt fired.
The UCRXIFG bit is not set!
I used the sample from Resource explorer. Here is the code:
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//******************************************************************************
// MSP430FR413x Demo - USCI_A0 External Loopback test @ 115200 baud
//
// Description: This demo connects TX to RX of the MSP430 UART
// The example code shows proper initialization of registers
// and interrupts to receive and transmit data. If data is incorrect P4.0 LED is
// turned ON.
// ACLK = n/a, MCLK = SMCLK = BRCLK = DCODIV ~1MHz.
//
// MSP430FR4133
// -----------------
// /|\| |
// | | |
// --|RST |
// | |
// | |
// | P1.0/UCA0TXD|----
// | | |
// | P1.1/UCA0RXD|----
// | |
// | P4.0 |--> LED
// | |
// Darren Lu
// Texas Instruments Inc.
// June 2014
// Built with IAR Embedded Workbench v6.10 & Code Composer Studio v6.0
//******************************************************************************
#include <msp430.h>
unsigned char RXData = 0;
unsigned char TXData = 100;
int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
PM5CTL0 &= ~LOCKLPM5; // Disable the GPIO power-on default high-impedance mode
// to activate previously configured port settings
P4DIR |= BIT0;
P4OUT &= ~BIT0; // P4.0 out low
// Configure UART pins
P1SEL0 |= BIT0 | BIT1; // set 2-UART pin as second function
// Configure UART
UCA0CTLW0 |= UCSWRST; // Put eUSCI in reset
UCA0CTLW0 |= UCSSEL__SMCLK;
// Baud Rate calculation
UCA0BR0 = 8; // 1000000/115200 = 8.68
UCA0MCTLW = 0xD600; // 1000000/115200 - INT(1000000/115200)=0.68
// UCBRSx value = 0xD6 (See UG)
UCA0BR1 = 0;
UCA0CTLW0 &= ~UCSWRST; // Initialize eUSCI
UCA0IE |= UCRXIE; // Enable USCI_A0 RX interrupt
RTCCTL &= ~RTCIE;
UCA0CTLW0 |= UCRXEIE;
_enable_interrupt();
while (1)
{
while(!(UCA0IFG & UCTXIFG));
UCA0TXBUF = TXData++; // Load data onto buffer
__bis_SR_register(LPM0_bits|GIE); // Enter LPM0
__no_operation(); // For debugger
}
}
#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,USCI_UART_UCTXCPTIFG))
{
case USCI_NONE: break;
case USCI_UART_UCRXIFG:
UCA0IFG &=~ UCRXIFG; // Clear interrupt
RXData = UCA0RXBUF; // Clear buffer
if(RXData != TXData) // Check value
{
P4OUT |= BIT0; // If incorrect turn on P4.0
while(1); // trap CPU
}
TXData++; // increment data byte
__bic_SR_register_on_exit(LPM0_bits); // Exit LPM0 on reti
break;
case USCI_UART_UCTXIFG: break;
case USCI_UART_UCSTTIFG: break;
case USCI_UART_UCTXCPTIFG: break;
}
}
I added only 3 lines of code:
RTCCTL &= ~RTCIE;
UCA0CTLW0 |= UCRXEIE;
_enable_interrupt();
Any help will be highly appreciated!
