Problem with fifo API (How to use fifo correctly)

Altera_Forum · ‎03-02-2015

Good day! I collect my system using: nios nco, fir and cic filters. In my case I use dsp-processor for control nco. NCO require AvST bridge, so I decided to use fifo between nios and nco.

First, I decided to make such system: NIOS, which store code frequency for nco (32 bits word), when fifo (I use it like a bridge AvMM-AvST) and second fifo (as bridge AvST-AvMM). In this system I want to write one word to fifo and read it, but have some problems and also simulate it in Modelsim.

But I have some problem - you can see my word didn't read/write via fifo. I suggest there are some problem in the code - may be I didn't adjust fifo correctly.

I use fifo's API:

1) altera_avalon_fifo_init – init fifo

2) altera_avalon_fifo_write_fifo – write to fifo

3) altera_avalon_fifo_read_fifo – read from fifo

My code:


/*
 * main.c
 *
 *  Created on: 26.02.2015
 *      Author: Roman
 */
//Includes# include "io.h"# include "altera_avalon_fifo_regs.h"# include "altera_avalon_fifo_util.h"# include "system.h"# include "sys/alt_irq.h"# include <stdio.h># include <stdlib.h># define ALMOST_EMPTY 2# define ALMOST_FULL FIFO_0_IN_CSR_FIFO_DEPTH-3
int main(){
    //reset the fifo's irq history register
    altera_avalon_fifo_clear_event(FIFO_0_IN_CSR_BASE,
                                   ALTERA_AVALON_FIFO_EVENT_ALL);
    //First FIFO (AvMM - AvST)
    int b = 0xab;
    //initializes the FIFO wr
    altera_avalon_fifo_init(FIFO_0_IN_CSR_BASE,            //the base address of the FIFO control slave
                            0,                            //the value to write to the interruptenable register
                            ALMOST_EMPTY,                //the value for the almost empty threshold (&#1087;&#1086;&#1088;&#1086;&#1075;) level
                            ALMOST_FULL);                //the value for the most full threshold  level
    //write a, b into fifo
    altera_avalon_fifo_write_fifo(FIFO_0_IN_BASE,             //the base address of the fifo write slave
                                 FIFO_0_IN_CSR_BASE,         //the base address of the fifo control slave
                                 b);                        //value to write to address
    //read a,b from fifo
    altera_avalon_fifo_read_fifo(FIFO_0_IN_BASE,             //the base address of the fifo read slave
                                 FIFO_0_IN_CSR_BASE);        //the base address of the fifo control slave
//Second FIFO (AvST - AvMM)
        //initializes the FIFO
        e = altera_avalon_fifo_init(FIFO_1_IN_CSR_BASE,            //the base address of the FIFO control slave
                                0,                            //the value to write to the interruptenable register
                                ALMOST_EMPTY,                //the value for the almost empty threshold (&#1087;&#1086;&#1088;&#1086;&#1075;) level
                                ALMOST_FULL);                //the value for the most full threshold  level
        //write d into fifo
        g = altera_avalon_fifo_write_fifo(FIFO_1_OUT_BASE,             //the base address of the fifo write slave
                                    FIFO_1_IN_CSR_BASE,         //the base address of the fifo control slave
                                     d);                        //value to write to address
        //read e,f from fifo
        h = altera_avalon_fifo_read_fifo(FIFO_1_OUT_BASE,             //the base address of the fifo read slave
                                        FIFO_1_IN_CSR_BASE);        //the base address of the fifo control slave
    return 0;
}

I will glad to hear all your advices.

Altera_Forum · ‎03-03-2015

Does anybody work with FIFO in Nios, using API?

Altera_Forum · ‎05-26-2015

hello ,

my nios II/e have to write on my Fifo.

i don't have a probleme with Qsys or Quartus.

my problem is the c program on nios eclipse.

Can you help me ?