C code question !! / NIOS II / SPI interface

[Altera_Forum]

Hello, 

 I have a question about implementing the spi interface in a FPGA, I already constructed a working CPU with a implementation of the SPI, and added the correct settings in SOIC, however i have a problem with my code for the niosII proccesor, for some reason it jumps right over my written code, it jumps straigt to the end of the main() function, I am as you would say a nOOb in programming... so i think i just made a stupid mistake in my code, but I cannot locate it...    Below states the code that i have written, for testing purpose's my idea was to send 0xFF a thousand times.... however when i go in debug mode it goes into int alt_avalon_spi_command(alt_u32 base, alt_u32 slave,......) and after that it jumps strait to the end without execucution the code under it.   The development board is a NIOS development board, Cyclone I edition...   I hope one of you could explain what i am doing wrong !! :confused:    Thanks a lot !! :)    greetings,   Remko      # include <stdio.h># include <system.h># include <altera_avalon_pio_regs.h> //#include <altera_avalon_pwm_routines.h> //#include <altera_avalon_uart_regs.h># include <string.h># include <sys/alt_alarm.h># include <alt_types.h># include <sys/time.h># include <fcntl.h>   //SPI headers# include <altera_avalon_spi_regs.h># include <altera_avalon_spi.h> int delay_1(); int spi();   int main() {  int alt_avalon_spi_command(alt_u32 base, alt_u32 slave, alt_u32 write_length, const alt_u8* wdata, alt_u32 read_length, alt_u8* read_data, alt_u32 flags) { int i; // force SS_N active IOWR_ALTERA_AVALON_SPI_CONTROL(base, ALTERA_AVALON_SPI_CONTROL_SSO_MSK); for (i = 0; i<10000 ; ++i) { // transmit a byte while (!(IORD_ALTERA_AVALON_SPI_STATUS(base) & ALTERA_AVALON_SPI_STATUS_TRDY_MSK)); IOWR_ALTERA_AVALON_SPI_TXDATA(base, 0xFF);   // wait for all bytes to be send while(!(IORD_ALTERA_AVALON_SPI_STATUS(base) & ALTERA_AVALON_SPI_STATUS_TMT_MSK)); } //release SS_N IOWR_ALTERA_AVALON_SPI_CONTROL(base, ~ALTERA_AVALON_SPI_CONTROL_SSO_MSK);   } delay_1(); }     int delay_1() {  int count = 0; int delay; while(1) {   IOWR_ALTERA_AVALON_PIO_DATA(LED_PIO_BASE, count & 0x03); IOWR_ALTERA_AVALON_PIO_DATA(SEVEN_SEG_PIO_BASE, count & 0xff); delay = 0; while(delay < 200000) { delay++; } count++; }  }

[Altera_Forum]

Why do you define a alt_avalon_spi_command function inside main()? 

Just put your code directly inside main() and it will run.  I didn't even know this was legal in C...

[Altera_Forum]

Thanks for the quick reply !! Well, thats a example .c file didint knew that would be a problem. But i don't quite understand what you mean by putting it int main(), if I define alt_avalon_spi_command () somewhere else than in main(); the code will not be accepted as then it will not reconise functions as IOWR_ALTERA_AVALON_SPI_CONTROL(base); I dont fully understandt the alt_avalon_spi_command(), although i have read the software reference, could you maybe give me a example CTRL+C, CTRL+V of my code by what you meant by putting the code inside main()... I have tried it but it didn't work for me...

[Altera_Forum]

Hey, kind of funny to reply to my own thread :p, but i have solved the problem! just as you suggested i can't define alt_avalon_spi_command function inside main()... stupid me... it was already defined in the header file... stupid mistake.... 

 thanks again for your reply !    greets,   remko

[Altera_Forum]

Hi, I read your code and it´s the only help about programming a SPI interface on a DE2... my question is if you can post your final code, because I have huge problems with programming it at NIOS eclipse and it will be a huge help to me... thanks for your time and help... :)

[Altera_Forum]

Hello, that's a long time ago, I need to find it first ;), but that won't be a problem, I will post it as soon as I can :)

[Altera_Forum]

Hi there, after a lot of searching i have found the code you requested :) 

 The data is sent 1 byte at a time, i have called it data, good luck with it ;)  int SPI (int data) {  /*  * Discard any stale data present in the RXDATA register, in case  * previous communication was interrupted and stale data was left  * behind.  */   IORD_ALTERA_AVALON_SPI_RXDATA(SPI_0_NVRAM_BASE);    // initiate SS_N  IOWR_ALTERA_AVALON_SPI_CONTROL(SPI_0_NVRAM_BASE, ALTERA_AVALON_SPI_CONTROL_SSO_MSK);    // transmit a byte, set write enable latch  while (!(IORD_ALTERA_AVALON_SPI_STATUS(SPI_0_NVRAM_BASE) & ALTERA_AVALON_SPI_STATUS_TRDY_MSK));  IOWR_ALTERA_AVALON_SPI_TXDATA(SPI_0_NVRAM_BASE, data);    // wait for all bytes to be send  while(!(IORD_ALTERA_AVALON_SPI_STATUS(SPI_0_NVRAM_BASE) & ALTERA_AVALON_SPI_STATUS_TMT_MSK));    // release SS_N  IOWR_ALTERA_AVALON_SPI_CONTROL(SPI_0_NVRAM_BASE, ~ALTERA_AVALON_SPI_CONTROL_SSO_MSK);  }

[Altera_Forum]

how can i clean the LCD ? is there any function?

[Altera_Forum]

Hi... thanks about the code... but it is only a function? or is a entire c program? well I need to send a byte to a slave, but I don´t know what "includes" put in my main code... if you know about it, please tell me... :)

[Altera_Forum]

Hi, 

 I would like o implement SPI with NIOS II in Qsys. I want NIOS to read and write data from a memory outside with SPI interface. Does this code work? I think it only sends data and while sending data to the memory is this function is enough and you don't deal with addresses and stuff.  Thanks

[Altera_Forum]

There is also a register you can use to read back the data that was received from the SPI bus. Have a look at the SPI IP documentation. 

The SPI IP just sends and reads back a bunch of bits. It has no idea about the protocol underneath and you need to do it yourself. So to deal with "addresses and stuff", have a look at your SPI memory datasheet and see how you should implement the protocol.

[Altera_Forum]

Hi, 

  I did not mean that actually, I know it only transfers data but does not know their meaning or if this comes this is to be done information. What I am trying to ask is how do I get it from SPI buffer to my memory or to NIOS (which are the two sides in my system NIOS-SPI-RAM ) and also I have an information in NIOS and I want to send it to RAM how do I do that where do I select where on the memory is data to be written.   Let me explain what I did. In Qsys I connect NIOS instruction and data master to SPI core's control port and connect SPI's conduit end a memory. I use this function in NIOS "alt_avalon_spi_command" to read or write data. What more should I do?  Thanks

[Altera_Forum]

I'm not sure I understand your problem. What kind of RAM are you using? Is it an external SPI RAM? From your other thread here (http://www.alteraforum.com/forum/showthread.php?t=39915&p=164635#post164635) it doesn't seem to be the case, but in that case why are you connecting it to the SPI component?

[Altera_Forum]

Hi; 

 I am now connecting it to an SPI component but I could not manage to program the NIOS. Where do I put my code? I created the Qsys project and generated it and with SOPC file I tried to use Eclipse to program the code but I could not manage it. Can you tell be how to do it I am a newbie I would appreciate any step even if you think it is natural.  Thank you Ugur

[Altera_Forum]

From Eclipse you should generate a BSP for your project and a sample "hello world" application. If you look on the Altera web site I think you'll find a "my first nios 2" tutorial that should describe how to do it.