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ac16串口程序--供大家讨论

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阅读(1980)

MC9S08AC16串口程序

使用MC9S08AC16单片机的串口接收数据,然后将接收到的数据回送至上位机。单片机总线频率20Mhz,串口通信波特率9600,下面是程序代码。

#include /* for EnableInterrupts macro */
#include "derivative.h" /* include peripheral declarations */

void clock_init(void){
/* Common initialization of the write once registers */
/* SOPT: COPE=0,COPT=1,STOPE=0,??=1,??=0,??=0,??=1,??=1 */
SOPT=0x53;
/* System clock initialization */
/* ICGC1: HGO=0,RANGE=1,REFS=1,CLKS1=1,CLKS0=1,OSCSTEN=1,LOCD=0,??=0 */
ICGC1=0x7C;
/* ICGC2: LOLRE=0,MFD2=0,MFD1=1,MFD0=1,LOCRE=0,RFD2=0,RFD1=0,RFD0=0 */
ICGC2=0x30;
if (*(unsigned char*)0xFFBE != 0xFF) { /* Test if the device trim value is stored on the specified address */
ICGTRM = *(unsigned char*)0xFFBE; /* Initialize ICGTRM register from a non volatile memory */
}
while(!ICGS1_LOCK) {; /* Wait */
}
}
/*
** ===================================================================
** Method : uart1_init (component AsynchroSerial)
**
** Description :
** Initializes the associated peripheral(s) and the bean internal
** variables. The method is called automatically as a part of the
** application initialization code.
** This method is internal. It is used by Processor Expert only.
** ===================================================================
*/
void uart1_init(void)
{
/* SCI1C1: LOOPS=0,SCISWAI=0,RSRC=0,M=0,WAKE=0,ILT=0,PE=0,PT=0 */
SCI1C1=0x00; /* Configure the SCI */
/* SCI1C3: R8=0,T8=0,TXDIR=0,TXINV=0,ORIE=0,NEIE=0,FEIE=0,PEIE=0 */
SCI1C3=0x00; /* Disable error interrupts */
/* SCI1S2: LBKDIF=0,RXEDGIF=0,??=0,RXINV=0,RWUID=0,BRK13=0,LBKDE=0,RAF=0 */
SCI1S2=0x00;
/* SCI1C2: TIE=0,TCIE=0,RIE=0,ILIE=0,TE=0,RE=0,RWU=0,SBK=0 */
SCI1C2=0x00; /* Disable all interrupts */
SCI1BDH = 0x00; /* Set high divisor register (enable device) */
SCI1BDL = 0x82; /* Set low divisor register (enable device) */
SCI1C2_TE = 0x01; /* Enable transmitter */
SCI1C2_RE = 0x01; /* Enable receiver */
}
/*
** ===================================================================
** Method : uart1_recvchar (component AsynchroSerial)
**
** Description :
** If any data is received, this method returns one
** character, otherwise it returns an error code (it does
** not wait for data). This method is enabled only if the
** receiver property is enabled.
** [Note:] Because the preferred method to handle error and
** break exception in the interrupt mode is to use events
** <&111nError> and the return value ERR_RXEMPTY has
** higher priority than other error codes. As a consequence
** the information about an exception in interrupt mode is
** returned only if there is a valid character ready to be
** read.
** Parameters :
** NAME - DESCRIPTION
** * Chr - Pointer to a received character
** Returns :
** --- - Error code, possible codes:
** ERR_OK - OK
** ERR_SPEED - This device does not work in
** the active speed mode
** ERR_RXEMPTY - No data in receiver
** ERR_BREAK - Break character is detected
** (only when the
** property is disabled and the ** signal> property is enabled)
** ERR_COMMON - common error occurred (the
** method can be used for error
** specification)
** ===================================================================
*/
unsigned char uart1_recvchar(unsigned char *ch)
{
unsigned char Result = 0; /* Return error code */
unsigned char StatReg = SCI1S1; /* Read status register */
if (StatReg & (SCI1S1_OR_MASK|SCI1S1_NF_MASK|SCI1S1_FE_MASK|SCI1S1_PF_MASK)) { /* Is any error set? */
Result = 0; /* If yes then set common error value */
}
else if (!(StatReg & SCI1S1_RDRF_MASK)) { /* Is the reciver empty and no error is set? */
return 0; /* If yes then error */
}
else {
/* Intentionally left empty due to compatibility with MISRA rule 60*/
*ch = SCI1D; /* Read data from the receiver */
Result=1;
}
return Result; /* Return error code */
}
/*
** ===================================================================
** Method : uart1_sendchar (component AsynchroSerial)
**
** Description :
** Sends one character to the channel. If the bean is
** temporarily disabled (Disable method) SendChar method
** only stores data into an output buffer. In case of a zero
** output buffer size, only one character can be stored.
** Enabling the bean (Enable method) starts the transmission
** of the stored data. This method is available only if the
** transmitter property is enabled.
** Parameters :
** NAME - DESCRIPTION
** Chr - Character to send
** Returns :
** --- - Error code, possible codes:
** ERR_OK - OK
** ERR_SPEED - This device does not work in
** the active speed mode
** ERR_TXFULL - Transmitter is full
** ===================================================================
*/
unsigned char uart1_sendchar(unsigned char ch)
{
if (!SCI1S1_TDRE) { /* Is the transmitter empty? */
return 0; /* If no then error */
}
SCI1D = (unsigned char)ch; /* Store char to the transmitter register */
return 0; /* OK */
}
void main(void) {
unsigned char ch;
EnableInterrupts; /* enable interrupts */
/* include your code here */
clock_init();
uart1_init();
for(;;) {
if(uart1_recvchar(&ch)){
uart1_sendchar(ch);
}

// __RESET_WATCHDOG(); /* feeds the dog */
} /* loop forever */
/* please make sure that you never leave main */
}
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