interrupt in LPC2148

Development Boards MicroMod
1

Dear all,

i have pasted the uart interrupt program…it doesn’t give any output on hyper terminal,during step by step execution i didn’t enter into the interrupt service loop…

Any one can guide me where I’m doing mistake…

#include<LPC214x.h>

#include<stdio.h>

void UART0_IN(void)__irq;

void serial(void);

int main()

{

IODIR1=0x00FF0000; //port direction control register

serial();

PINSEL0=0x00000005; //pin function select register

VICIntSelect=0x00000040;//enable VIC channel as FIQ

VICVectAddr0=(unsigned int )UART0_IN;

VICVectCntl12=0x20 | 6; //enable uart0 interrupt slot6

VICIntEnable=0x00000040;//enable uart0 interrupt in vic

}

void UART0_IN(void)__irq

{

while(!(U0LSR&0x01));

U1THR=‘J’;

VICVectAddr=0;

}

2

I’d recommend trying to get it to work as a normal IRQ instead of an FIQ first. If you are using an FIQ I believe you have to install the FIQ handler into the system’s FIQ interrupt address.

Also the VICVectAddr0 / VICVectCtrl2 combination doesn’t look right to me. Check the VIC chapter in the LPC2148 User Manual (UM10139)

3

There are lots of examples of code on handling the LPC21xx UART. Here’s some I wrote…

// I/O syntax is from IAR's .h files
#define vectorNo xxx // index
        VICIntEnClear = (1<<VIC_UART0); // disable UARTn interrupt
        PINSEL0 |= (1<<0); // _bit.P0_0 = 1;  //Uart0 TX function select pins 0,1
        PINSEL0 |= (1<<2); // _bit.P0_1 = 1;  //Uart0 RX function select       
        // setup VIC for interrupts from UART
        VICIntSelect &= ~(1<<VIC_UART0); // mark as vectored, not FIQ
        VICVectAddresses[vectorNo] = (unsigned int)&UART0_isr; // Install ISR in VIC addr slot 
        VICVectControls[vectorNo] = 0x20 | VIC_UART0;        // IRQ type, int enabled
        // now setup the baud rate, etc

__irq __arm void UART0_isr(void)
{
  UART_isr(0);
}  Interrupt Function: handle any UARTx TX and RX interrupt
  *************************************************************************/
__arm void UART_isr(unsigned char uartNo)
{  
  struct UART_UARTBUF *uartBuf; // pointer to UART buffer managemement
  struct LPC_UART *uartio; // pointer to hardware registers
  unsigned char ch, IIRwas, rx;

  // pointer to buffer management for the interrupting UART
  uartBuf = &uartBufs[uartNo];
  // pointer to hardware registers for the interrupting UART
  uartio = uartBuf->iobase;
  
  // Process all pending TX or RX interrupts...

  while ( ( (IIRwas = uartio->IIR) & 1) == 0) { // interrupt request is pending if 0 
    switch( (IIRwas >> 1) & 7)  { // Interrupt ID. Table 89 in LPC manual    
      
// etc, etc