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Hello
I am facing a problem in the following code.
code :-
#include "LPC318x.h" void IRQ_HANDLER(void) __irq { PIO_OUTP_SET = 0x7EFFFFFF; PIO_OUTP_SET = 0x7EFFFFFF; }
int main (void) { unsigned int i=0; SYSCLK_CTRL = 0x00000140; HCLKPLL_CTRL = 0x00014024; UARTCLK_CTRL = 0x0F; MIC_ER = 0x000007C0; U5LCR = 0x03; U5CLK = 0x0000020E; UART_CLKMODE = 0x00000550; U5FCR = 0x00; U5IER = 0x07; U3DLL = 27;
while(1) {
U5THR = 0x55; U5THR = 0xAA; }
}
When i enable UART5 interrupt by using MIC_ER interrupt is generated as it should be. But after transmitting the data it jumps to an unusual location 0x000002d4. But it doesnt go to IRQ handler. If i don't enable the interrupt using MIC_ER then it executes only while(1) loop. The main aim of the program is to blink the LED after send data through UART5 as mentioned in the IRQ interrupt handler.
Thank You,
Ankit Thakkar.
hello
I checked again. It was my fault. It enters into interrupt mode as the interrupt is generated but it doesn't find any interrupt handler at the location. I checked in the map file that IRQ_Handler is assigned an address in the memory map. As it doesnt find any IRQ handler it goes into ABORT mode. I need to add IRQ handler at the location assigned to IRQ_Handler in the map file. But i dont know how to add that IRQ handler. Let me know if any body familiar with this kind of problem.
Regards,
Ankit thakkar.
I haven't worked with any LPC31xx chips, but the LPC21xx and 23xx chips has special VIC control registers where you assign the pointer to the interrupt handler.
If you just look at example code for your processor, you should find a number of examples where an interrupt handler is defined, and where the interrupt controller is configured to know where the interrupt handler is located. The command "grep" is your friend. If you can't installed a "grep" application on your machine, to quickly google for a Win32 version and install. It helps when you want to quickly scan example code or header files for specific details.
That is the problem that LPC3180 doesnt have vectored interrupt controller. It has one main interrupt controller and two sub interrupt controllers. So i have to write down an interrupt handler for IRQ and then in that interrupt handler i have to find that which peripheral has generated interrupt. And LPC3180 is a new device so there is not much support or sample codes available. I made following changes in the PHYTEC_LPC3000.s.
IMPORT IRQ_Handler instead of IRQ_Handler B IRQ_Handler
And then i defined IRQ_Handler in my application code. But still it doesnt work.
A vectored interrupt controller may be cool, but not needed. Your processor still have an interrupt vector table, where you hard-code pointers to interrupt handlers.
You should have something like:
Vectors LDR PC,Reset_Addr LDR PC,Undef_Addr LDR PC,SWI_Addr LDR PC,PAbt_Addr LDR PC,DAbt_Addr DCD ||Image$$ER_ROM$$RO$$Length||+\ ||Image$$RW_RAM1$$RW$$Length|| LDR PC,IRQ_Addr LDR PC,FIQ_Addr Reset_Addr DCD Reset_Handler Undef_Addr DCD Undef_Handler SWI_Addr DCD SWI_Handler PAbt_Addr DCD PAbt_Handler DAbt_Addr DCD DAbt_Handler DCD 0 ; Reserved Address IRQ_Addr DCD IRQ_Handler FIQ_Addr DCD FIQ_Handler Undef_Handler B Undef_Handler SWI_Handler B SWI_Handler PAbt_Handler B PAbt_Handler DAbt_Handler B DAbt_Handler IRQ_Handler B IRQ_Handler FIQ_Handler B FIQ_Handler
in your startup file.
When you replaced the IRQ_Handler dummy-loop with an import - did you also write an assembler function IRQ_Handler or did you go for a C function with the __irq keyword?
You can set a breakpoint directly in the vector table, to allow you to follow the interrupt all the way from the start.
Yes i wrote IRQ_Handler named function in the code.
I am posting my code and interrupt vector table code in the header file.
Header file code :-
Vectors LDR PC,Reset_Addr LDR PC,Undef_Addr LDR PC,SWI_Addr LDR PC,PAbt_Addr LDR PC,DAbt_Addr ;DCD ||Image$$ER_IROM1$$RO$$Length||+||Image$$RW_IRAM1$$RW$$Length|| DCD 0x4000 ;PHYTEC comment: This hard codes the size ;that the secondary bootloader uses to copy ;binary software to SDRAM.
LDR PC,IRQ_Addr LDR PC,FIQ_Addr
Reset_Addr DCD Reset_Handler Undef_Addr DCD Undef_Handler SWI_Addr DCD SWI_Handler PAbt_Addr DCD PAbt_Handler DAbt_Addr DCD DAbt_Handler DCD 0 ; Reserved Address IRQ_Addr DCD IRQ_Handler FIQ_Addr DCD FIQ_Handler
Undef_Handler B Undef_Handler SWI_Handler B SWI_Handler PAbt_Handler B PAbt_Handler DAbt_Handler B DAbt_Handler FIQ_Handler B FIQ_Handler IMPORT IRQ_Handler
My application code :-
void IRQ_Handler(void) { MIC_ER &= 0xFFFFFFFC; led_blink(); MIC_ER = 0x00000003; }
I have defined this kind of IRQ_Handler in my application code.
Now when IRQ is generated it should execute IRQ_Handler function. But it goes in to ABORT mode. When i check SPSR in ABORT mode it shows that it had been into IRQ mode before entering into ABORT.
1) Your code does not look like mine. Might you have missed the posting instructions for source code? Visible just above the text box when you write a message.
2) You don't specify that your "interrupt handler" really is an interrupt handler. How will the compiler know to produce the suitable prologue/epiloge code? That was why I mentioned the __irq keyword in my previous post.
Yes.. You are right.. i mentioned __irq keyword now. But it doesn't jump at the location of handler shown in the map file. But I am not clear with prologue/epilogue code. Can you please tell me what is that? I presume it to be something like that by using it the processor decides where to jump when the interrupt is generated.
Google is your friend:
en.wikipedia.org/.../Function_prologue
And have you seen if you can single-step all the way from the interrupt vector table?
yeah.. i got abt prologue and epilogue. i checked in a single step execution. Eventhough after the generation of interrupt it doesn't jump anywhere in the program and just executes the instructions in the normal sequence. So i can not jump to any interrupt handler while executing instructions in single step mode. When i run the code by pressing f5 it handles the interrupt and the processor goes into IRQ mode. The location it jumps is 0x000001BC. the location mentioned for IRQ routine is 0x800001A0 which is the address of OFFCHIP SRAM. As i believe the IRQ routine is placed from OFFCHIP SRAM to onchip SRAM for faster execution. I dont have any clue where IRQ is stored in onchip SRAM.
Did you test what happens if you set a breakpoint in the startup file?
yeah i placed break points on the vector table points as shown below.
Undef_Handler B Undef_Handler SWI_Handler B SWI_Handler PAbt_Handler B PAbt_Handler DAbt_Handler B DAbt_Handler IRQ_Handler B IRQ_Handler FIQ_Handler B FIQ_Handler
When IRQ is generated and i press F5 it should go to interrupt vector table but PROGRAM counter doesn't go there.
You still haven't read the instructions for posting code, which makes any code you post look completely garbled...
Note that the vector table in itself is an array of addresses which may make it impossible to take an interrupt there. You are probably limited to putting breakpoints on the first instruction pointed at by the vector table entries.
sorry for bad code posting. you are right that interrupt vector itself is an array of addresses but when it enters into IRQ mode it loads program counter by the starting address of IRQ routine. which is LDR instruction. I have placed breakpoints on that instructions. So when it enters into IRQ mode it should load PC by IRQ routine starting address. But it doesn't execute the instruction. again i m posting the code where i placed the breakpoints in startup file
Vectors LDR PC,Reset_Addr LDR PC,Undef_Addr LDR PC,SWI_Addr LDR PC,PAbt_Addr LDR PC,DAbt_Addr ;DCD ||Image$$ER_IROM1$$RO$$Length||+||Image$$RW_IRAM1$$RW$$Length|| DCD 0x4000 ;PHYTEC comment: This hard codes the size ;that the secondary bootloader uses to copy ;binary software to SDRAM. LDR PC,IRQ_Addr LDR PC,FIQ_Addr
And i placed breakpoints when CPSR is changed when it enters into IRQ mode and loads SP.
Enter IRQ Mode and set its Stack Pointer MSR CPSR_c, #Mode_IRQ:OR:I_Bit:OR:F_Bit MOV SP, R0 SUB R0, R0, #IRQ_Stack_Size
i have placed breakpoints on all the points as shown in the code. but PC doesn't even enter in that code.
Does the address after LDR match the address of your IRQ handler as seen from the map file?
Have you tried to add breakpoints for all the other vectors?
HEY when i place more than two break points in the program and try to run it. it executes code upto first break point but then the execution stops there. it doesnt go ahead by pressing F5. Even it doesnt go ahead if i press F10 or F11. Thats strange. When i debug step by step using F11 it doesnt execute using F5. I am doing onchip debugging and ETB module of LPC3180 supports upto two breakpoints at a time only. So i dont reach on the exact address location where IRQ starting address is located.
Much can be done with only two breakpoints.
You may have to run the application multiple times, trying different locations for your breakpoints.