HELP,I can't generate Hardware interrupt

[Altera_Forum]

I need help,please 

 What I want is : When I press a button ON Board, Nios Let LEDs lights.Of course,the LEDs is turned off before.(The board is DIY,Just a cyclone ep1c3t144c8 without flash and sdram.I download program to On_chip 4K ram for test. this is a test board,later I will make Nios with flash and sdram on PCB.SO,thanks for advice!!)  the Problem is,Software is make just like nios example: nios\examples\software\count_binary   software:  static void handle_button_interrupts(void* context, alt_u32 id) {    IOWR_ALTERA_AVALON_PIO_EDGE_CAP(0x1820, 0);  //0x1820 is the addbase, input of my button for interrupts  //problem is not getin here,I put breakpoint here,but never stop!      IOWR_ALTERA_AVALON_PIO_DATA(0x1830,0xf);//Let leds light! // 0x1830 is the addbase of leds   }  int alt_main (void) {  alt_u8 led = 0x00;  alt_u16 i=0x0;  alt_u16 j=0x0;  alt_u8 inbit;      IOWR_ALTERA_AVALON_PIO_IRQ_MASK(0x1820, 0xf);  IOWR_ALTERA_AVALON_PIO_EDGE_CAP(0x1820, 0x0);    j=alt_irq_register( 0, 0, handle_button_interrupts );  //The first para is 0:the IRQ on SOPC,I set it as 0 //the 2nd para is 0: the number to interrupt ,I set it 0 //the 3rd para is handle_button_interrupts:my interrupt gate! //I set breakpoint here,after this instruction ,j gets 0.it indicate that registe success!  ......   the NIos developer's handbook says: Button is pressed, generating an IRQ. But when I press the button,Irq didn't generate!!   The step I make SOPC: In SOPC,When I set key_in_pio,(IP is PIO),  1.In the first Dialog window,Width set "1"bits.and choose"Input ports only."   2.In the 2nd Dialog window,I just let it Generate IRQ, I choose "Level".then Pressed finish.  Then in the main window,I set pio's IRQ as"0";  other IP:cpu,led pio,key_in_pio,onchip memory_0;  Out of the FPGA,I let a Key to triger .When I press button,the level is 3.3v;otherwise the level is 0v;   Thanks for spending time on reading this.

[Altera_Forum]

- better to use edge triggered interrupts in your input pio 

- i don't know if you need a system timer, this normally  has IRQ0 assigned.  does your program runs normal in debugger  e.g let a led blink in while loop ?   .. .. while(1) {  usleep(100000);  led ^= 0x01;  IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE,led);  }

[Altera_Forum]

Fischer, http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif  

  thanks,I will try to use IRQ1,and use edg.  the LED is OK in normal test(It can lights and blank),and I will let it blank in the interrupt test program when the irq not generate!.

[Altera_Forum]

Fischer, 

 I am afraid ,I also can&#39;t get IRQ. I found that "status" is always &#39;0&#39;.it means IE is not enable. I thought the register can enable IE,I don&#39;t know I miss what .

[Altera_Forum]

http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/sad.gif  

 I also found that there is a weird problem:   the instruction :  //r2=10 WRCTL ienable,r2 ........    but after this instructon ,I traced the debug in disassumbly,the ienable didn&#39;t change.  can anyone help!

[Altera_Forum]

Hello TommyCP, 

 i tried the following in an ep1c3t144 chip, quartus 5.1 nios 5.1, and it works as expected. in to schematic i have: input clk : 50Mhz input reset_n , connected to VCC in fpga inport button [7..0] (PIO_0) outport led [7..0] )PIO_1)     cpu nios II/e jtag debug module: 0x00..0x7ff onchip memory 4k add: 0x1000..0x1fff pio_0 8 bit input only,sync capture faling edge, generate irq edge add: 0x800 irq:0 pio_1 8 bit output only  add: 0x810  uses hello world small as start and modified it as following  switch on input 0 generates irq and toggles output 1 output 0 is toggled in while loop  program compiles:  make -s all  Compiling hello_world_small.c... ../hello_world_small.c: In function `main&#39;: ../hello_world_small.c:88: warning: passing arg 2 of `alt_irq_register&#39; discards qualifiers from pointer target type Linking hello_world_small_1.elf... Info: (hello_world_small_1.elf) 2080 Bytes program size (code + initialized data). Info: 2016 Bytes free for stack + heap. Post-processing to create onchip_memory_0.dat Post-processing to create onchip_memory_0.hex Post-processing to create onchip_memory_0.sym Build completed  # include <stdio.h># include <unistd.h> // usleep()# include "system.h"# include "sys/alt_irq.h"# include "altera_avalon_pio_regs.h"   static void handle_button_interrupts(void* context, alt_u32 id);  volatile alt_u8 led=0; /* A variable to hold the value of the button pio edge capture register. */ volatile int edge_capture; volatile int irq_count; # define BUTTON_PIO_BASE PIO_0_BASE# define BUTTON_PIO_IRQ PIO_0_IRQ# define LED_PIO_BASE PIO_1_BASE  int main() {   // Enable all 4 button interrupts.   IOWR_ALTERA_AVALON_PIO_IRQ_MASK(BUTTON_PIO_BASE, 0xf); // Reset the edge capture register.   IOWR_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE, 0x0); // Register the interrupt handler.   alt_irq_register( BUTTON_PIO_IRQ,&edge_capture, handle_button_interrupts );     while(1) {  usleep(100000);  led ^= 0x01;  IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE,led);  }  return 0; }   static void handle_button_interrupts(void* context, alt_u32 id) { // Cast context to edge_capture&#39;s type. It is important that this be  // declared volatile to avoid unwanted compiler optimization. //   volatile int* edge_capture_ptr = (volatile int*) context; // Store the value in the Button&#39;s edge capture register in *context.   *edge_capture_ptr = IORD_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE); // Reset the Button&#39;s edge capture register.   IOWR_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE, 0);  led^=0x02;  IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE,led); // irq_count++; }

[Altera_Forum]

Fischer, 

I really thank you a lot. I will do exactly as you did.  http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif

[Altera_Forum]

Fischer, 

I actually works as expects,thanks a lot. now the instruction  "WRCTL ienable,r2"  works,It can enable IRQ.  the difference between us: you uses "hello world small" as start,while I use"hello led". other different like :memory addr,input triger(you use &#39;fall edge&#39;;I &#39;rise edge&#39; ),and some I think less important set.   all in all.thank you a lot! Best wishs.

[Altera_Forum]

I have met the same problem before. 

So far, I don&#39;t know the root reason cause this issue. I just try to modify the IRQ, and sometimes it works, sometimes not...