📄 fet140_uart11_19200_2.c
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//******************************************************************************
// MSP-FET430P140 Demo - USART1, UART 19200 Echo ISR, XT2 HF XTAL SMCLK
//
// Description: Echo a received character, RX ISR used. Normal mode is LPM0,
// USART1 RX interrupt triggers TX Echo. Though not required, MCLK= XT2.
// ACLK =n/a, MCLK = SMCLK = UCLK1 = XT2 = 8MHz
// Baud rate divider with 8Mhz XTAL @19200 = 8MHz/19200 = 416.66 ~ 417 (01A0h)
// //* An external 8MHz XTAL on X2IN X2OUT is required for XT2CLK *//
// //* Min Vcc required varies with MCLK frequency - refer to datasheet *//
//
// MSP430F149
// -----------------
// /|\| X2IN|-
// | | | 8Mhz
// --|RST X2OUT|-
// | |
// | P3.6|------------>
// | | 19200 - 8N1
// | P3.7|<------------
//
//
// M. Buccini
// Texas Instruments Inc.
// Feb 2005
// Built with IAR Embedded Workbench Version: 3.21A
//******************************************************************************
#include <msp430x14x.h>
void main(void)
{
volatile unsigned int i;
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P3SEL |= 0xC0; // P3.6,7 = USART1 option select
BCSCTL1 &= ~XT2OFF; // XT2on
do
{
IFG1 &= ~OFIFG; // Clear OSCFault flag
for (i = 0xFF; i > 0; i--); // Time for flag to set
}
while ((IFG1 & OFIFG)); // OSCFault flag still set?
BCSCTL2 |= SELM_2 + SELS; // MCLK= SMCLK= XT2 (safe)
ME2 |= UTXE1 + URXE1; // Enable USART1 TXD/RXD
UCTL1 |= CHAR; // 8-bit character
UTCTL1 |= SSEL1; // UCLK = SMCLK
UBR01 = 0xA0; // 8Mhz/19200 ~ 417
UBR11 = 0x01; //
UMCTL1 = 0x00; // no modulation
UCTL1 &= ~SWRST; // Initialize USART state machine
IE2 |= URXIE1; // Enable USART1 RX interrupt
_BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}
#pragma vector=UART1RX_VECTOR
__interrupt void usart1_rx (void)
{
while (!(IFG2 & UTXIFG1)); // USART1 TX buffer ready?
TXBUF1 = RXBUF1; // RXBUF1 to TXBUF1
}
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