Interruption program

Hello,

I do not know exactly the context when working with video, but for the interruption, as in your previous program you have to acknowledge the interruption in the ISR (like write on the edgecapture register for PIO port).

Jérôme

Hi Jerome,

The only registers I have are those below and I don't see which one could correspond to the edgecapture register.

The line "IOWR(video_in_base[0], 0x0, 0x08 )" enables the interruption. I tried to put it in the ISR but no more success.

# define VIDEO_1_NAME "/dev/video_1"# define VIDEO_1_TYPE "bitec_qvideo_in"# define VIDEO_1_BASE 0x00008000# define VIDEO_1_SPAN 128# define VIDEO_1_IRQ 1# define ALT_MODULE_CLASS_video_1 bitec_qvideo_in

Given the registers, do you have an idea ?

Thank you for your help,

Myriam

Can you put a picture of your design to well understand the context please.

Else, the variable context here is just to save values during ISR. For example in the count_binary example, you have the following :

 1 /* A variable to hold the value of the button pio edge capture register. */
 2 volatile int edge_capture;
 3 static void init_button_pio()
 4 {
 5     /* Recast the edge_capture pointer to match the alt_irq_register() function
 6      * prototype. */
 7     void* edge_capture_ptr = (void*) &edge_capture;
 8     /* Enable all 4 button interrupts. */
 9     IOWR_ALTERA_AVALON_PIO_IRQ_MASK(BUTTON_PIO_BASE, 0xf);
10     /* Reset the edge capture register. */
11     IOWR_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE, 0x0);
12     /* Register the interrupt handler. */
13     alt_irq_register( BUTTON_PIO_IRQ, edge_capture_ptr,
14                       handle_button_interrupts );
15 }
16 static void handle_button_interrupts(void* context, alt_u32 id)
17 {
18     /* Cast context to edge_capture's type. It is important that this be 
19      * declared volatile to avoid unwanted compiler optimization.
20      */
21     volatile int* edge_capture_ptr = (volatile int*) context;
22     /* Store the value in the Button's edge capture register in *context. */
23     *edge_capture_ptr = IORD_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE);
24     /* Reset the Button's edge capture register. */
25     IOWR_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE, 0);
26     IORD_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE); //An extra read call to clear of delay through the bridge
27 
28 }

In the ISR, you get the value of the edge capture register to know which button has been pushed, and store it at the address pointed by edge_capture_ptr. This variable point to the same address as context (line 21). And context has the same address as edge_capture variable (line 13 and 7).

Hi Jerôme,

I attached two pictures of my top level entity. I am thus trying to interrupt video1. Thanks for your explanation of the context. The problem is that I don't see the context here... The interruption is automatically generated at the end of each frame and I see nothing in the registers which could register the context.

Myriam

Hi,

About the context forget it for the moment. It is not compulsory to use it. For example you can register the ISR like that.

 alt_irq_register( BUTTON_PIO_IRQ, 0, handle_button_interrupts ); 

And in the ISR function, you do not use the variable context. But it is not the problem, so forget it for the moment.

So if I understand well, the interrupt is active when you have activity on the LSB of your video port. What is the name of this signal on your design ?

To be sure if you have an interruption and the program goes to the ISR, you can switch on a LED in the ISR. Like that you know rapidly if the problem is here or not.

After, as it is a the video port is a PIO port, like in your design with the buttons, the principle is the same. In the ISR, you have to write on the edgecapture register for PIO port (IOWR_ALTERA_AVALON_PIO_EDGE_CAP(VIDEO_1_BASE, 0xFF)).

Jérôme

Hello,

I don't manage to add buttons and led to my design. Indeed, I based my design on an example given by BITEC on their website. I changed .v files but never changed SoPC files. When I regenerate SOPC without changing anything, the design does not work anymore. I have then a time limited .sof so maybe I am missing some licenses (?) and some files are not correctly regenerated (?). Therefore, I can't touch to SoPC.

However, I used your piece of advice and noticed first that like you said, I did not acknoledge the interruption which I did (it is not a PIO port but I found the way to do it). Second, my interruption signal was not generated. Now, it prints "coincoin" :) (see my first post). This means it goes to the ISR. The problem is that whether or not I generate an irq, the video (that is to say the rest of my program) does not work anymore.

At least, when there is no irq generated, the rest of the program (which is the while (1)) should work, right ? Do I have to disable/enable something ?

Do you have an idea where it may come from ?

Your help is very precious !

Myriam

Hello,

Sorry but I am not sure of what you say (I have to improve my english). If you don't have interruption the video works. And if you enable it, it does not work. Is that correct, or it never works ?

If it never works, I have no idea because I never works with this design. So what I recommend is to use the default design provide by BITEC, check that it works, and modify it little by little until you have what you want.

If it is the interruption that cause problem, like that I don't see where that can coming from. Maybe if you can give details of the different steps of your program please.

Else, I missed it before, but you should change the following (I don't know the effect that can have)

if (pouet == 1)
    {printf("coincoin");
        pouet == 0;
    }

by

if (pouet == 1)
    {printf("coincoin");
        pouet = 0;
    }

Jérôme

Hi Jérôme,

Thanks for the "equal error" ! I managed to have my design work. As my interruption was not on a PIO, I got confused. Actually, I did not need masks for my interruption so I removed this line and my design worked !

Once more, thank you for your help.

Myriam

Hi,

Ok, so your design work as you want, or you still have problem or mysterious things to clarify ?

Otherwise, I'm glad to have help you.

Jérôme

Hi Jérôme,

I am glad you ask because I do have a really mysterious error !

Like I told you before, I have a design with a cpu, onchip mem, a ssram, a flash memory interface, a tristate bridge, a jtag,a i2c bus (BITEC module), a vga and 2 video inputs (those are also BITEC modules).

It was extracted from an example which worked. Until now, I never changed anything in SoPC. I made a test and generated sopc again without changing anything. Then, I have the following errors in NIOS (without changing my C code either). I have 32KBytes onchip mem with 32 bit wide data.

I made another test and implemented an easy "Hello world" which does not work either ! Do you have an idea where it may come from ? I am really lost there !

Myriam

Here is what is written in NIOS II :

make -s all includes

Compiling main4.c...

Linking hsmc_quad_video_mosaic.elf...

/cygdrive/c/altera/90/nios2eds/bin/nios2-gnutools/H-i686-pc-cygwin/bin/../lib/gcc/nios2-elf/3.4.6/../../../../nios2-elf/bin/ld: region onchip_mem is full (hsmc_quad_video_mosaic.elf section .text). Region needs to be 20832 bytes larger.

/cygdrive/c/altera/90/nios2eds/bin/nios2-gnutools/H-i686-pc-cygwin/bin/../lib/gcc/nios2-elf/3.4.6/../../../../nios2-elf/bin/ld: address 0x1fd54 of hsmc_quad_video_mosaic.elf section .onchip_mem is not within region onchip_mem

collect2: ld returned 1 exit status

make: *** [hsmc_quad_video_mosaic.elf] Error 1

Build completed in 6.828 seconds