模拟串口！

zhoulongshaxia

模拟串口！ [复制链接]

各位大哥有谁有430模拟串口的C程序啊？能给我参考一下啊！先谢谢了

luliku

搜一下，就有了

anuana

我找到的就是汇编的，能不能是C的啊？

louis920_2001

顶一下，呵呵

cancan_919

//******************************************************************************
// MSP-FET430x110 Demo - Timer_A, Ultra-Low Pwr UART 9600 String, 32kHz ACLK
//
// Description: This program demonstrates a half-duplex 9600-baud UART using
// Timer_A3 and a 32kHz crystal. The program will wait in LPM3, and will
// respond to a received 'u' character using 8N1 protocol. The response will be
// the string 'Hello World. The Set_DCO subroutine will calibrate the DCOCLK
// to ~2MHz, which will is used as the Timer_A clock.
// ACLK = LFXT1/8 = 32768/8, MCLK = SMCLK = target DCO
// //* External watch crystal installed on XIN XOUT is required for ACLK *//
//
// MSP430F1121
// -----------------
// /|\| XIN|-
// | | | 32kHz
// --|RST XOUT|-
// | |
// | CCI0A/TXD/P1.1|-------->
// | | 9600 8N1
// | CCI0B/RXD/P2.2|<--------
//
#define RXD 0x04 // RXD on P2.2
#define TXD 0x02 // TXD on P1.1

// Conditions for 9600 Baud SW UART, DCO ~ 2MHz

#define Bitime_5 104 // ~ 0.5 bit length
#define Bitime 208 // ~ 9615 baud
#define DELTA 488 // Target DCO = DELTA*(4096) ~2MHz

unsigned int RXTXData;
unsigned char BitCnt;
unsigned char i;
unsigned int Compare, Oldcapture;

void TX_Byte (void);
void RX_Ready (void);

// M. Buccini
// Texas Instruments Inc.
// Feb 2005
// Built with IAR Embedded Workbench Version: 3.21A
//******************************************************************************

#include <msp430x11x1.h>


static char string1[] = { "Hello World\r\n" };

void main (void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
BCSCTL1 |= DIVA_3; // ACLK = LFXT1CLK/8
CCTL0 = OUT; // TXD Idle as Mark
CCTL2 = CM_1 + CCIS_1 + CAP + CCIE; // CAP, ACLK, interrupt
TACTL = TASSEL_2 + MC_2; // SMCLK, continuous mode
P1SEL = TXD; // P1.1/TA0 for TXD function
P1DIR = TXD; // TXD output on P1
P2SEL = RXD; // P2.2/TA0 as RXD input

// Mainloop
for (;;)
{
RX_Ready(); // UART ready to RX one Byte
_BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interr until char RXed

if (RXTXData == 'u') // 'u' received?
{
i=0;
do
{
RXTXData = string1[i];
TX_Byte(); // TX Back RXed Byte Received
i++;
}
while (i < sizeof string1-1);
}
}
}


// Function Transmits Character from RXTXData Buffer
void TX_Byte (void)
{
BitCnt = 0xA; // Load Bit counter, 8data + ST/SP
CCR0 = TAR; // Current state of TA counter
CCR0 += Bitime; // Some time till first bit
RXTXData |= 0x100; // Add mark stop bit to RXTXData
RXTXData = RXTXData << 1; // Add space start bit
CCTL0 = OUTMOD0 + CCIE; // TXD = mark = idle
while ( CCTL0 & CCIE ); // Wait for TX completion
}


// Function Readies UART to Receive Character into RXTXData Buffer
// Sync capture not possi××e as DCO=TACLK=SMCLK can be off !!
void RX_Ready (void)
{
BitCnt = 0x8; // Load Bit counter
CCTL0 = CM1 + CCIS0 + OUTMOD0 + CAP + CCIE; // Neg Edge, Cap
}


// Timer A0 interrupt service routine
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A0 (void)
{
CCR0 += Bitime; // Add Offset to CCR0

// RX
if (CCTL0 & CCIS0) // RX on CCI0B?
{
if( CCTL0 & CAP ) // Capture mode = start bit edge
{
CCTL0 &= ~ CAP; // Switch from capture to compare mode
CCR0 += Bitime_5;
_BIC_SR_IRQ(SCG1 + SCG0); // DCO reamins on after reti
}
else
{
RXTXData = RXTXData >> 1;
if (CCTL0 & SCCI) // Get bit waiting in receive latch
RXTXData |= 0x80;
BitCnt --; // All bits RXed?
if ( BitCnt == 0)
//>>>>>>>>>> Decode of Received Byte Here <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
{
CCTL0 &= ~ CCIE; // All bits RXed, disa××e interrupt
_BIC_SR_IRQ(LPM3_bits); // Clear LPM3 bits from 0(SR)
}
//>>>>>>>>>> Decode of Received Byte Here <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
}
}
// TX
else
{
if ( BitCnt == 0)
CCTL0 &= ~ CCIE; // All bits TXed, disa××e interrupt
else
{
CCTL0 |= OUTMOD2; // TX Space
if (RXTXData & 0x01)
CCTL0 &= ~ OUTMOD2; // TX Mark
RXTXData = RXTXData >> 1;
BitCnt --;
}
}
}



// Timer_A3 Interrupt Vector (TAIV) handler
#pragma vector=TIMERA1_VECTOR
__interrupt void Timer_A1 (void)
{
switch( TAIV )
{
case 2: break; // CCR1 not used
case 4:
{
Compare = CCR2; // Get current captured SMCLK
Compare = Compare - Oldcapture; // SMCLK difference
Oldcapture = CCR2; // S××e current captured SMCLK
if (DELTA < Compare)
{
DCOCTL--;
if (DCOCTL == 0xFF) // DCO is too fast, slow it down
{
if (!(BCSCTL1 == (XT2OFF + DIVA_3)))
BCSCTL1--; // Did DCO role under?, Sel lower RSEL
}
}
else
{
DCOCTL++; // DCO is too slow, speed it down
if (DCOCTL == 0x00)
{
if (!(BCSCTL1 == (XT2OFF + DIVA_3 + 0x07)))
BCSCTL1++; // Did DCO role over? Sel higher RSEL
}
}
}
case 10: break; // Not used
}
}

strawroot

谢谢斑竹和大哥！呵呵

mars_v

mark