serial port read problem

im doing the project in lpc 1768.. for my project i have to read the serial port value from the cc2431 zigbee node..but i couldnt read the serial port value..while debugging the execution stops in the while loop in the serial read that is while (SER_BUF_EMPTY(ser_in));

board:MCB1700
baud rate:38400
code:

#include <RTL.h>
#include <stdio.h>
#include <LPC17xx.H>
#include "serial.c"

int main()
{

int a;
int len=10;
char b[10];
ser_OpenPort(1);
ser_InitPort1 (38400,8,0,1);
a=ser_Read(b,&len);
printf("%d",a);
ser_ClosePort(1);

}

serial.c:

#include "LPC17xx.h"

/*---------------------------------------------------------------------------- Defines for ring buffers *---------------------------------------------------------------------------*/
#define SER_BUF_SIZE (128) // serial buffer in bytes (power 2)
#define SER_BUF_MASK (SER_BUF_SIZE-1ul) // buffer size mask
#define SystemFrequency 50000000
/* Buffer read / write macros */
#define SER_BUF_RESET(serBuf) (serBuf.rdIdx = serBuf.wrIdx = 0)
#define SER_BUF_WR(serBuf, dataIn) (serBuf.data[SER_BUF_MASK & serBuf.wrIdx++] = (dataIn))
#define SER_BUF_RD(serBuf) (serBuf.data[SER_BUF_MASK & serBuf.rdIdx++])
#define SER_BUF_EMPTY(serBuf) (serBuf.rdIdx == serBuf.wrIdx)
#define SER_BUF_FULL(serBuf) (serBuf.rdIdx == serBuf.wrIdx+1)
#define SER_BUF_COUNT(serBuf) (SER_BUF_MASK & (serBuf.wrIdx - serBuf.rdIdx))

// buffer type
typedef struct __SER_BUF_T
{

unsigned char data[SER_BUF_SIZE]; unsigned int wrIdx; unsigned int rdIdx;

} SER_BUF_T;

unsigned long ser_txRestart; // NZ if TX restart is required
unsigned short ser_lineState; // ((msr << 8) | (lsr))
SER_BUF_T ser_out; // Serial data buffers
SER_BUF_T ser_in;

/*---------------------------------------------------------------------------- open the serial port *---------------------------------------------------------------------------*/
void ser_OpenPort (char portNum)
{

if ( portNum == 0 )

{ /* Port 0 */ NVIC_DisableIRQ(UART0_IRQn); LPC_PINCON->PINSEL0 &= ~0x000000F0; LPC_PINCON->PINSEL0 |= 0x00000050; /* RxD0 is P0.3 and TxD0 is P0.2 */ }

else

{ /* Port 1 */ NVIC_DisableIRQ(UART1_IRQn); LPC_PINCON->PINSEL4 &= ~0x0000000F; LPC_PINCON->PINSEL4 |= 0x0000000A; /* Enable RxD1 P2.1, TxD1 P2.0 */ }

return;

}

/*---------------------------------------------------------------------------- close the serial port *---------------------------------------------------------------------------*/

void ser_ClosePort (char portNum )
{

if ( portNum == 0 )

{ /* POrt 0 */ LPC_PINCON->PINSEL0 &= ~0x000000F0; /* Disable the interrupt in the VIC and UART controllers */ LPC_UART0->IER = 0; NVIC_DisableIRQ(UART0_IRQn); }

else

{ /* Port 1 */ LPC_PINCON->PINSEL4 &= ~0x0000000F; /* Disable the interrupt in the VIC and UART controllers */ LPC_UART1->IER = 0; NVIC_DisableIRQ(UART1_IRQn); }

return;

}
/*---------------------------------------------------------------------------- initialize the serial port *---------------------------------------------------------------------------*/

void ser_InitPort1 (unsigned long baudrate, unsigned int databits, unsigned int parity, unsigned int stopbits)

{

unsigned char lcr_p, lcr_s, lcr_d; unsigned int dll; unsigned int pclkdiv, pclk;

switch (databits)
{ case 5: // 5 Data bits lcr_d = 0x00; break; case 6: // 6 Data bits lcr_d = 0x01; break; case 7: // 7 Data bits lcr_d = 0x02; break; case 8: // 8 Data bits default: lcr_d = 0x03; break;

}

switch (stopbits)

{

case 1: // 1,5 Stop bits case 2: // 2 Stop bits lcr_s = 0x04; break; case 0: // 1 Stop bit default: lcr_s = 0x00; break; }

switch (parity)

{

case 1: // Parity Odd lcr_p = 0x08; break; case 2: // Parity Even lcr_p = 0x18; break; case 3: // Parity Mark lcr_p = 0x28; break; case 4: // Parity Space lcr_p = 0x38; break; case 0: // Parity None default: lcr_p = 0x00; break; }

SER_BUF_RESET(ser_out); // reset out buffer SER_BUF_RESET(ser_in); // reset in buffer

/* Bit 8,9 are for UART1 */ pclkdiv = (LPC_SC->PCLKSEL0 >> 8) & 0x03;

switch ( pclkdiv )

{ case 0x00: default: pclk = SystemFrequency/4; break; case 0x01: pclk = SystemFrequency; break; case 0x02: pclk = SystemFrequency/2; break; case 0x03: pclk = SystemFrequency/8; break; }

dll = (pclk/16)/baudrate ; /*baud rate */ LPC_UART1->FDR = 0; // Fractional divider not used LPC_UART1->LCR = 0x80 | lcr_d | lcr_p | lcr_s; // Data bits, Parity, Stop bit LPC_UART1->DLL = dll; // Baud Rate depending on PCLK LPC_UART1->DLM = (dll >> 8); // High divisor latch LPC_UART1->LCR = 0x00 | lcr_d | lcr_p | lcr_s; // DLAB = 0 LPC_UART1->IER = 0x03; // Enable TX/RX interrupts

LPC_UART1->FCR = 0x07; /* Enable and reset TX and RX FIFO. */ ser_txRestart = 1; // TX fifo is empty

/* Enable the UART Interrupt */ NVIC_EnableIRQ(UART1_IRQn); return;
}

/*---------------------------------------------------------------------------- read data from serial port *---------------------------------------------------------------------------*/
int ser_Read (char *buffer, const int *length)

{

int bytesToRead, bytesRead;

/* Read *length bytes, block if *bytes are not avaialable */

bytesToRead = *length; bytesToRead = (bytesToRead < (*length)) ? bytesToRead : (*length); bytesRead = bytesToRead;

while (bytesToRead--)

{ while (SER_BUF_EMPTY(ser_in)); // Block until data is available if none *buffer++ = SER_BUF_RD(ser_in);

}

return (bytesRead);

}