我用413模仿串口收发数据，只能接纳单个字节，用串口帮手调试时发现413发送给PC机的字节不正确。
比方串口帮手发0xaa给413，413接纳后把0xaa发送回给PC机，可是串口帮手接纳到的是0x00或其他数据，
为什么？怎样才能完结一串数据的收发正确？
程序如下（晶振是32768，接413的8和9脚）：
#include <msp430x41x.h>
#define RXD 0x0002 // RXD on P1.1
#define TXD 0x0002 // TXD on P2.1
#define RS485 0x0001 //enable 485 on P2.0
// Conditions for 2400 Baud SW UART, ACLK = 32768
#define Bitime_5 0x06 // ~ 0.5 bit length + small adjustment
#define Bitime 0x0E // 427us bit length ~ 2341 baud
unsigned int RXTXData;
unsigned char BitCnt;
void Delay(unsigned int i);
void TX_Byte(void);
void RX_Ready(void);
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
FLL_CTL0 |= XCAP14PF; // Configure load caps
CCTL0 |= OUT; // TXD Idle as Mark
TACTL = TASSEL_1 + MC_1; // ACLK, continous mode
P1SEL |= RXD;
P1DIR &= ~RXD;
P2SEL |= TXD;
P2DIR |= TXD;
P2DIR |= RS485;
P2OUT &= ~RS485;
_EINT();
// Mainloop
for(;;)
{
RX_Ready(); // UART ready to RX one Byte
_BIS_SR(LPM3_bits + GIE); // Enter LPM3 Until character RXed
TX_Byte(); // TX Back RXed Byte Received
}
}
void Delay(unsigned int i)
{
unsigned char j;
for(j = 0; j < 5; j ++)
while(i–);
}
// Function Transmits Character from RXTXData Buffer
void TX_Byte(void)
{
P2OUT |= RS485;
Delay(10);
P2OUT &= ~RS485;
BitCnt = 0x0A; // Load Bit counter, 8data + ST/SP
CCR0 = TAR; // Current state of TA counter
CCR0 += Bitime; // Some time till first bit
RXTXData |= 0x0100; // 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
void RX_Ready(void)
{
BitCnt = 0x08; // Load Bit counter
CCTL0 = SCS + CCIS0 + OUTMOD0 + CM1 + CAP + CCIE; // Sync, Neg Edge, Capture
}
// Timer A0 interrupt service routine
interrupt [TIMERA0_VECTOR]
void TimerA0_ISR(void)
{
CCR0 += Bitime; // Add Offset to CCR0
// RX————————————————————————–
if(CCTL0 & CCIS0) // RX on CCI0B?
{
if(CCTL0 & CAP) // Capture mode = start bit edge
{
CCTL0 &= ~CAP; // Capture to compare mode
CCR0 += Bitime_5;
}
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, disable 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, disable interrupt
else
{
CCTL0 |= OUTMOD2; // TX Space
if(RXTXData & 0x0001)
CCTL0 &= ~OUTMOD2; // TX Mark
RXTXData = RXTXData >> 1;
BitCnt–;
}
}
}
请各位大虾不吝珠玉！！！
lsdfae18
2006-10-13, 11:49
参阅这个程序吧
#define RXD 0x02 // RXD on P1.1
#define TXD 0x01 // TXD on P1.0
// Conditions for 2400 Baud SW UART, ACLK = 32768
#define Bitime_5 0x06 // ~ 0.5 bit length + small adjustment(14/2=7)
#define Bitime 0x0E // 427us bit length ~ 2341 baud (14/32768=427.246us，32768/14=2340.571428)
unsigned int RXTXData;
unsigned char BitCnt; //位计数
void TX_Byte (void);
void RX_Ready (void);
// M.Buccini
// Texas Instruments, Inc
// March 2002
//******************************************************************************
#include
void main (void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer(封闭看门狗模块)
FLL_CTL0 |= XCAP14PF; // Configure load caps(装备振荡器电容)
CCTL0 = OUT; // TXD Idle as Mark(捕获/比较寄存器0：输出高电平)
TACTL = TASSEL0+MC1; // ACLK, continous mode(守时器A：ACLK时钟，接连计数模式)
P1SEL = TXD + RXD; // PP1.0/1 TA0 for TXD/RXD function(TA0引脚功用)
P1DIR = TXD; // TXD output on P1(输出引脚)
// Mainloop
for (;;)
{
RX_Ready(); // UART ready to RX one Byte(为等候开始位到来作预备)
_BIS_SR(LPM3_bits+GIE); // Enter LPM3 Until character RXed
TX_Byte(); // TX Back RXed Byte Received(回传收到的字节)
}
}
// Function Transmits Character from RXTXData Buffer
void TX_Byte (void)
{
BitCnt = 0xA; // Load Bit counter, 8data + ST/SP(发送10位数据)
CCR0 = TAR; // Current state of TA counter(守时器计数器当时值放比较寄存器中)
CCR0 += Bitime; // Some time till first bit(后推一位的时刻)
RXTXData |= 0x100; // Add mark stop bit to RXTXData(填充中止位)
RXTXData = RXTXData << 1; // Add space start bit(填充开始位)
CCTL0 = OUTMOD0+CCIE; // TXD = mark = idle(置位输出形式，答应中止)
while ( CCTL0 & CCIE ); // Wait for TX completion(等候发送完结)
}
// Function Readies UART to Receive Character into RXTXData Buffer
void RX_Ready (void)
{
BitCnt = 0x8; // Load Bit counter(接纳8位)
CCTL0 = SCS+CCIS0+OUTMOD0+CM1+CAP+CCIE; // Sync, Neg Edge, Capture
//(CCIxB引脚同步下降沿捕获，置位输出形式，答应中止)
}
// Timer A0 interrupt service routine
interrupt[TIMERA0_VECTOR] void Timer_A (void)
{
CCR0 += Bitime; // Add Offset to CCR0(下一守时时刻为1位时刻)
// RX(接纳字节)
if (CCTL0 & CCIS0) // RX on CCI0B?(假如CCI0B是捕获输入引脚)
{
if( CCTL0 & CAP ) // Capture mode = start bit edge(假如是在捕获形式，则是在等候开始位)
{
CCTL0 &= ~ CAP; // Switch from capture to compare mode(得到开始位后改为比较形式)
CCR0 += Bitime_5; //守时方位改到位的中心方位(加半个位的时刻)
}
else
{
RXTXData = RXTXData >> 1; //先收到的是低位
if (CCTL0 & SCCI) // Get bit waiting in receive latch
RXTXData |= 0x80; //SCCI中锁存的是比较持平时的输入引脚上的信号
BitCnt –; // All bits RXed? //位计数减1
if ( BitCnt == 0) //接纳完一个字节?
//>>>>>>>>>> Decode of Received Byte Here <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
{
CCTL0 &= ~ CCIE; // All bits RXed, disable interrupt(接纳完一个字节后制止中止)
_BIC_SR_IRQ(LPM3_bits); // Clear LPM3 bits from 0(SR)(预备退出低功耗形式)
}
//>>>>>>>>>> Decode of Received Byte Here <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
}
}
// TX(发送字节，在进入发送中止前现已置位OUTMOD0)
else
{
if ( BitCnt == 0) //一切位发送完结
CCTL0 &= ~ CCIE; // All bits TXed, disable interrupt(制止中止)
else
{
CCTL0 |= OUTMOD2; // TX Space(输出形式OUTMOD2+OUTMOD0：复位)
if (RXTXData & 0x01)
CCTL0 &= ~ OUTMOD2; // TX Mark(输出形式OUTMOD0：置位)
RXTXData = RXTXData >> 1; //低位先发
BitCnt –; //位计数
}
}
}
