I am having trouble getting the interrupt to work when data is
received on UART0. I have verified that the UART is working, both
sending an receiving. I am using GNUARM, any pointers would be great.
//main.c
#include
#include "lpc2103.h"
#include "uart.h"
char data;
unsigned char test = 0;
void UNDEF_Routine();
void SWI_Routine();
void IRQ_Routine()__attribute__ ((interrupt("IRQ")));
void FIQ_Routine();
void UNDEF_Routine(){}
void SWI_Routine(){}
void IRQ_Routine() {
U0IIR |= 0x01; /* Clear Interrupt */
test = 1;
data = U0RBR;
VICVectAddr = 0x0;
}
void FIQ_Routine(){}
void delay(void) {
int i = 10000;
while(i > 0) {
i--;
}
}
int main (void)
{
unsigned int i;
unsigned char temp;
initUART0(9600);
U0IER = 0x1;
VICVectAddr0 = (unsigned long)IRQ_Routine;
VICVectCntl0 = 0x20 | 6;
VICIntEnable = 0x40;
U0FCR = 0x07;
IODIR |= 1<<26; // P0.26 is an output
while( 1 ) {
delay();
IOSET = 1<<26; //LED off
delay();
for( i = 0; i < 10000; i++ );
IOCLR = 1<<26; //LED on
putstrUART0("Blah\n");
if(test == 1) {
putstrUART0("Interrupt\n");
test = 0;
}
}
}
//crt.s
/*
***************************************************************************************************************
crt.s STARTUP ASSEMBLY CODE
-----------------------
Module includes the interrupt vectors and start-up code.
***************************************************************************************************************
*/
/* Stack Sizes */
.set UND_STACK_SIZE, 0x00000004 /* stack for "undefined instruction"
interrupts is 4 bytes */
.set ABT_STACK_SIZE, 0x00000004 /* stack for "abort" interrupts is 4
bytes */
.set FIQ_STACK_SIZE, 0x00000004 /* stack for "FIQ" interrupts is 4
bytes */
.set IRQ_STACK_SIZE, 0X00000004 /* stack for "IRQ" normal interrupts
is 4 bytes */
.set SVC_STACK_SIZE, 0x00000004 /* stack for "SVC" supervisor mode
is 4 bytes */
/* Standard definitions of Mode bits and Interrupt (I & F) flags in
PSRs (program status registers) */
.set MODE_USR, 0x10 /* Normal User Mode */
.set MODE_FIQ, 0x11 /* FIQ Processing Fast
Interrupts Mode */
.set MODE_IRQ, 0x12 /* IRQ Processing Standard
Interrupts Mode */
.set MODE_SVC, 0x13 /* Supervisor Processing Software
Interrupts Mode */
.set MODE_ABT, 0x17 /* Abort Processing memory
Faults Mode */
.set MODE_UND, 0x1B /* Undefined Processing Undefined
Instructions Mode */
.set MODE_SYS, 0x1F /* System Running Priviledged
Operating System Tasks Mode */
.set I_BIT, 0x80 /* when I bit is set, IRQ is
disabled (program status registers) */
.set F_BIT, 0x40 /* when F bit is set, FIQ is
disabled (program status registers) */
.text
.arm
.global Reset_Handler
.global _startup
.func _startup
_startup:
# Exception Vectors
_vectors: ldr PC, Reset_Addr
ldr PC, Undef_Addr
ldr PC, SWI_Addr
ldr PC, PAbt_Addr
ldr PC, DAbt_Addr
nop /* Reserved Vector (holds Philips ISP
checksum) */
ldr PC, [PC,#-0xFF0] /* see page 71 of "Insiders
Guide to the Philips ARM7-Based Microcontrollers" by Trevor Martin */
ldr PC, FIQ_Addr
Reset_Addr: .word Reset_Handler /* defined in this module below */
Undef_Addr: .word UNDEF_Routine /* defined in main.c */
SWI_Addr: .word SWI_Routine /* defined in main.c */
PAbt_Addr: .word UNDEF_Routine /* defined in main.c */
DAbt_Addr: .word UNDEF_Routine /* defined in main.c */
IRQ_Addr: .word IRQ_Routine /* defined in main.c */
FIQ_Addr: .word FIQ_Routine /* defined in main.c */
.word 0 /* rounds the vectors and ISR addresses
to 64 bytes total */
# .=.+0x1C0 /* skip past Philips ISP ram usage (all the way to
0x40000200) */
# Reset Handler
Reset_Handler:
/* Setup a stack for each mode - note that this only sets up a
usable stack
for User mode. Also each mode is setup with interrupts initially
disabled. */
ldr r0, =_stack_end
msr CPSR_c, #MODE_UND|I_BIT|F_BIT /* Undefined Instruction
Mode */
mov sp, r0
sub r0, r0, #UND_STACK_SIZE
msr CPSR_c, #MODE_ABT|I_BIT|F_BIT /* Abort Mode */
mov sp, r0
sub r0, r0, #ABT_STACK_SIZE
msr CPSR_c, #MODE_FIQ|I_BIT|F_BIT /* FIQ Mode */
mov sp, r0
sub r0, r0, #FIQ_STACK_SIZE
msr CPSR_c, #MODE_IRQ|I_BIT|F_BIT /* IRQ Mode */
mov sp, r0
sub r0, r0, #IRQ_STACK_SIZE
msr CPSR_c, #MODE_SVC|I_BIT|F_BIT /* Supervisor Mode */
mov sp, r0
sub r0, r0, #SVC_STACK_SIZE
msr CPSR_c, #MODE_SYS|I_BIT|F_BIT /* User Mode */
mov sp, r0
/* copy .data section (Copy from ROM to RAM) */
ldr R1, =_etext
ldr R2, =_data
ldr R3, =_edata
1: cmp R2, R3
ldrlo R0, [R1], #4
strlo R0, [R2], #4
blo 1b
/* Clear .bss section (Zero init) */
mov R0, #0
ldr R1, =_bss_start
ldr R2, =_bss_end
2: cmp R1, R2
strlo R0, [R1], #4
blo 2b
/* Enter the C code */
b main
.endfunc
.end
