msp430f5529 simple uart source program (use the serial port assistant to send and receive replies)

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msp430f5529 simple uart source program (use the serial port assistant to send and receive replies) [Copy link]

The MCU source program is as follows:

1. /*****What to send with the serial assistant and what to reply****/
5. #include "msp430f5529.h"
6. // ACLK = REFO = 32768Hz, MCLK = SMCLK = default DCO/2 = 1048576Hz
7. // P3.4，5——USCI_A0 TXD/RXD；P9.4,5——USCI_A2 TXD/RXD；P10.4,5——USCI_A3 TXD/RXD；
8. void main(void)
9. {
10. WDTCTL = WDTPW + WDTHOLD; // Stop WDT
11. P4SEL |=BIT4+BIT5 ; // P5.6,7 = USCI_A1 TXD/RXD
12. UCA1CTL1 |= UCSWRST; // **Put state machine in reset**
13. UCA1CTL1 |= UCSSEL_2; // SMCLK
14. UCA1BR0 = 9; // 1MHz 115200 (see User's Guide)
15. UCA1BR1 = 0; // 1MHz 115200
16. UCA1MCTL |= UCBRS_1 + UCBRF_0; // Modulation UCBRSx=1, UCBRFx=0
17. UCA1CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
18. UCA1IE |= UCRXIE; // Enable USCI_A1 RX interrupt
19. __bis_SR_register(LPM0_bits + GIE); // Enter LPM0, interrupts enabled
20. }
21. // Echo back RXed character, confirm TX buffer is ready first, confirm the send buffer is ready before sending data
22. #pragma vector=USCI_A1_VECTOR
23. __interrupt void USCI_A1_ISR(void)
24. {
25. switch(__even_in_range(UCA1IV,4))
26. {
27. case 0:break; // Vector 0 - no interrupt
28. case 2: // Vector 2 - RXIFG
29. while (!(UCA1IFG&UCTXIFG)); // USCI_A1 TX buffer ready? UCTXIFG(USCI Transmit Interrupt Flag)
30. //Wait for data to be sent and then set UCTXIFG to 1 to exit the loop
31. UCA1TXBUF = UCA1RXBUF; // TX -> RXed character
32. break;
33. case 4:break; // Vector 4 - TXIFG
34. default: break;
35. }
36. }
37. // UCTXIFG = 0x02, UCA1IFG & UCTXIFG, when the UCTXIFG bit of UCA1IFG is 1, it means that UCA1TXBUF is empty.
38. //Break out of the while loop; when the UCTXIFG bit is 0, UCA1TXBUF is not empty, so stop in the loop.