Hi,
Please help
I have written a c code for LPC2378 microcontroller, inorder to set a timer0 and generate an interrupt whenever the timer overflow occurs and the interrupt is mapped to VIC timer0 vector address 4. The problem is while watching the timer and vector register values.............the overflow is happening finely, the interrupt is generated and notified to the VIC by changing the VIC vector address where the PC has to take control but the pc is not changed to that location to execute the subroutine. Please help me.
Please find my attached code.
#include <stdio.h> #include <LPC23xx.H> /* LPC23xx definitions */ __irq void T0_IRQHandler (void); int main (void) { /* Enable and setup timer interrupt, start timer */ T0MR0 = 10; T0MCR = 3; /* Interrupt and Reset on MR0 */ T0TCR = 1; /* Timer0 Enable */ T0PR = 10; /* Timer0 Enable */ VICVectAddr4 = (unsigned long)T0_IRQHandler;/* Set Interrupt Vector */ VICVectCntl4 = 15; /* use it for Timer0 Interrupt priority is 5*/ VICIntEnable = (1 << 4); /* Enable Timer0 Interrupt */ while(1) { } }
/* Import function for turning LEDs on or off */ /* Timer0 IRQ: Executed periodically */
__irq void T0_IRQHandler (void) { static int clk_cntr; clk_cntr++; if (clk_cntr >= 1000) { clk_cntr = 0; /* Activate flag every 1 second */ } T0IR = 1; /* Clear interrupt flag */ VICVectAddr = 0; /* Acknowledge Interrupt */ }
Check the contents of your Startup file - particularly any reference to the VICAddress register. The location is different from that used in the LPC21xx/LPC22xx MCUs. Was VIVVectAddr: 0xFFFF F030; now VICAddress: 0xFFFF FF00
For more details see the NXP Application note: AN10576 Migration to the LPC2300/LPC2400 family.
-- Regards, Chris Burrows Armaide v2.0: LPC2xxx Oberon-07 Development System www.cfbsoftware.com/armaide
VICVectCntl4 = 15; /* use it for Timer0 Interrupt priority is 5*/
I guess the above is incorrect.
From LPC23xx.h
/* The name convention below is from previous LPC2000 family MCUs, in LPC23xx/24xx, these registers are known as "VICVectPriority(x)". */ #define VICVectCntl0 (*(volatile unsigned long *)(VIC_BASE_ADDR + 0x200)) #define VICVectCntl1 (*(volatile unsigned long *)(VIC_BASE_ADDR + 0x204)) #define VICVectCntl2 (*(volatile unsigned long *)(VIC_BASE_ADDR + 0x208)) #define VICVectCntl3 (*(volatile unsigned long *)(VIC_BASE_ADDR + 0x20C)) #define VICVectCntl4 (*(volatile unsigned long *)(VIC_BASE_ADDR + 0x210))
Strictly, yes. However, although these have been renamed to indicate their current use more accurately the addresses remain unchanged. i.e. VICVectCntl0-15 == VICVectPriority0-15 so it should still work.
The comment is not quite right however. It should say:
...priority is 15*/
or better still, use the proper register name and remove the comment as it is then just stating the obvious ;-)
Hi Chris,
I think You are right. it should still work.
So, maybe the problem is caused by Mohana Ganesh didn't initialize the VIC?
Step 1. Initialize the VIC Step 2. Disable Timer0 Interrupt Step 3. Set and Enable Timer0 Interrupt
T0MR0 = 10;
10 is very very small, I think.
(This thread is too difficult to me.)
I agree - 10 is way too small. The system may be being swamped by interrupts. My LPC2378 interrupt example written in Oberon-07 works OK and in that I have set T1MR0 := 100000. The relevant code snippets (using Timer1) are:
Initialisation: (* Timer match value *) SYSTEM.PUT(LPC.T1MR0, 100000); (* MR0 Interrupt (MR0I: {0}) and Reset (MR0R: {1}) on match *) SYSTEM.PUT(LPC.T1MCR, {0, 1});
Module IRQTimer: PROCEDURE TimerHandler[4]; (* 4 for IRQ or FIQ *) BEGIN INC(timeVal); (* Clear the MR0 interrupt *) SYSTEM.PUT(LPC.T1IR, {0}); (* Update the VIC priority hardware *) SYSTEM.PUT(LPC.VICVectAddr, 0) END TimerHandler;
Client Module: PROCEDURE Wait(); VAR i: INTEGER; BEGIN i := IRQTimer.timeVal; WHILE ABS(IRQTimer.timeVal - i) < 100 DO END END Wait;
Chris Burrows CFB Software Armaide v2.0: LPC2xxx Oberon-07 Development System www.cfbsoftware.com/armaide
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