Tool/software: Code Composer Studio
I am trying to test the following code for testing UART on launchpad but upon running the code, the receive buffer (UCA0RXBUF) does not show any recieved hex code. Also, I have programmed an LED to switch off when the character from the transmit buffer(UCA0TXBUF) echoes to the recieve buffer(UCA0RXBUF). But it does not work. Requesting help!
#include <msp430.h> volatile unsigned int i; /* * main.c */ int main(void) { WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer // Set P2.0 and P2.1 for USCI_A0 UART operation P2SEL0 &= ~(BIT0 | BIT1); P2SEL1 |= BIT0 | BIT1; P1DIR |= BIT0; //conf LED at P1.0 for debugging P1OUT |= BIT0; //LED P1.0 switched on at startup // Disable the GPIO power-on default high-impedance mode to activate // previously configured port settings PM5CTL0 &= ~LOCKLPM5; // Startup clock system with max DCO setting ~8MHz CSCTL0_H = CSKEY >> 8; // Unlock clock registers CSCTL1 = DCOFSEL_3 | DCORSEL; // Set DCO to 8MHz CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK; CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1; // Set all dividers CSCTL0_H = 0; // Lock CS registers // Configure USCI_A0 for UART mode UCA0CTLW0 = UCSWRST; // enable software reset UCA0CTLW0 |= UCSSEL__SMCLK; // CLK = SMCLK // Baud Rate calculation // 8000000/(16*9600) = 52.083 // Fractional portion = 0.083 // UCBRFx = int ( (52.083-52)*16) = 1 UCA0BR0 = 52; // 8000000/16/9600 UCA0BR1 = 0x00; UCA0MCTLW |= UCOS16 | UCBRF_1 | 0x4900; UCA0CTLW0 &= ~UCSWRST; // Initialize eUSCI, disable software reset UCA0IE |= UCRXIE; // Enable USCI_A0 RX interrupt UCA0TXBUF = 0x41; //test send 'A' __bis_SR_register(LPM3_bits | GIE); // Enter LPM3, interrupts enabled __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: while(!(UCA0IFG & UCTXIFG)); UCA0TXBUF = UCA0RXBUF; //echo P1OUT &= ~BIT0; //LED P1.0 switched off __no_operation(); break; case USCI_UART_UCTXIFG: break; case USCI_UART_UCSTTIFG: break; case USCI_UART_UCTXCPTIFG: break; } }