Cours:Vhdl

Nios 2

interface pour le bus avalon

hardware

entity customPeriph is
    port (
        clk         : in  std_logic;
        reset_n     : in  std_logic;
        address     : in  std_logic_vector(1 downto 0);
        write       : in  std_logic;
        read        : in  std_logic;
        chipselect  : in  std_logic;
        writedata   : in  std_logic_vector(31 downto 0);
        readdata    : out std_logic_vector(31 downto 0)
    );
end entity customPeriph;

software

IOWR(CUSTOM_0_BASE,regNumber,value);

irq avec le nios2

hardware

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use ieee.std_logic_unsigned.all;


entity customIRQ is
    port (
        clk         : in  std_logic;
        reset_n     : in  std_logic;
        address     : in  std_logic_vector(1 downto 0);
        write       : in  std_logic;
        read        : in  std_logic;
        chipselect  : in  std_logic;
        writedata   : in  std_logic_vector(31 downto 0);
		  irq			  : out std_logic;
        readdata    : out std_logic_vector(31 downto 0);
		  bps : in std_logic_vector(9 downto 0)
    );
end entity customIRQ;

architecture rtl of customIRQ is

    signal s_irq     : std_logic;
    signal input     : std_logic_vector(9 downto 0);
    signal input_reg : std_logic_vector(9 downto 0);
    signal rd_data  : std_logic_vector(31 downto 0);
	 
begin

    --------------------------------------------------------
    -- Processus principal : écriture des registres
    --------------------------------------------------------
    process(clk, reset_n)
    begin
        if rising_edge(clk) then
            if chipselect = '1' and write = '1' then
                s_irq <= '0';
	    elsif input /= input_reg then
		s_irq <= '1';
            end if;
        end if;
    end process;
    irq <= s_irq;
end architecture rtl;

PIO

interruptions

static void myISR(void * context,alt_u32 id)
{
        // terminer par l'acquittement de l'interruption
	IOWR_ALTERA_AVALON_PIO_EDGE_CAP(PIO_0_BASE, 0);
	IORD_ALTERA_AVALON_PIO_EDGE_CAP(PIO_0_BASE);
}

int main()
{ 
  // choix des PIO déclenchant l'interruption
  IOWR_ALTERA_AVALON_PIO_IRQ_MASK(PIO_0_BASE, 0xff);
  // initialisation des fronts
  IOWR_ALTERA_AVALON_PIO_EDGE_CAP(PIO_0_BASE, 0);
  alt_ic_isr_register(PIO_0_IRQ_INTERRUPT_CONTROLLER_ID, PIO_0_IRQ ,(void *) myISR,NULL,NULL);
  while (1)
  {
  }
}