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Altera_Forum's avatar
Altera_Forum
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16 years ago

SPI Interface

Hej!

I just wanna know tht using Alteras SPI core...can anyone read the SD card as well. I m having some problem. I tried to use the altera Hal function

int alt_avalon_spi_command(....)

to write and read a location..but the thing is...when ever i read the address...the result is 255(all 1's in 8 bit)...but i have chkd the write code..and all the waveforms on the oscilloscope...i guess writing is done perfectly.bcz i wrote the same thing on the 7 seg display..and its working fine....but i cant say for sure..bcz i cant read...i have configured the SPI core as master...do we need to do something special...to read the card as well...i was thinking like..we need some kind of special core as well...to read the card.

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    HI,

    i have this probelm as well as you explain.

    Has somebody solve this problem ?

    thx
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Hi,

    I have implemented an SPI-Core for read/write a Micro-SD card from OC. The core has to be initialized as SD/MMC controller. Then he can perform block reads/writes to the card.

    I´m not sure if the SPI-Controller of altera can do that.
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    Thank you for you replay.

    Is that the SPI core , which works with wishbone ?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Yes,

    that´s right. You have to conect the wishbone signals with the nios signals in the top sheet.

    --- Quote Start ---

    module MICRO_SD_TOP

    ( //NIOSII

    input wire NIOS_CLK,

    input wire SPI_CLK, //48MHz

    input wire NIOS_CSn,

    input wire NIOS_WRn,

    input wire NIOS_RDn,

    input wire [5:0] NIOS_ADDR,

    input wire [3:0] NIOS_BE,

    input wire [31:0] NIOS_DATAout,

    output wire [31:0] NIOS_DATAin,

    input wire RESET,

    output wire NIOS_WAITREQn,

    //SD_CARD

    output wire SD_DATA_OUT,

    input wire SD_DATA_IN,

    output wire SD_CS,

    output wire SD_CLK

    );

    wire [7:0] SD_DATA_O;

    wire [7:0] SD_DATA_I;

    wire [7:0] SD_ADDR_I;

    assign NIOS_DATAin[7:0] = ( ~NIOS_CSn && ~NIOS_RDn && (NIOS_BE[3:0] == 4'b0001) ) ? SD_DATA_O[7:0] : 8'hzz;

    assign NIOS_DATAin[15:8] = ( ~NIOS_CSn && ~NIOS_RDn && (NIOS_BE[3:0] == 4'b0010) ) ? SD_DATA_O[7:0] : 8'hzz;

    assign NIOS_DATAin[23:16] = ( ~NIOS_CSn && ~NIOS_RDn && (NIOS_BE[3:0] == 4'b0100) ) ? SD_DATA_O[7:0] : 8'hzz;

    assign NIOS_DATAin[31:24] = ( ~NIOS_CSn && ~NIOS_RDn && (NIOS_BE[3:0] == 4'b1000) ) ? SD_DATA_O[7:0] : 8'hzz;

    assign SD_DATA_I[7:0] = ( ~NIOS_CSn && ~NIOS_WRn && (NIOS_BE[3:0] == 4'b0001) ) ? NIOS_DATAout[7:0] : 8'hzz;

    assign SD_DATA_I[7:0] = ( ~NIOS_CSn && ~NIOS_WRn && (NIOS_BE[3:0] == 4'b0010) ) ? NIOS_DATAout[15:8] : 8'hzz;

    assign SD_DATA_I[7:0] = ( ~NIOS_CSn && ~NIOS_WRn && (NIOS_BE[3:0] == 4'b0100) ) ? NIOS_DATAout[23:16] : 8'hzz;

    assign SD_DATA_I[7:0] = ( ~NIOS_CSn && ~NIOS_WRn && (NIOS_BE[3:0] == 4'b1000) ) ? NIOS_DATAout[31:24] : 8'hzz;

    assign SD_ADDR_I[7:2] = NIOS_ADDR[5:0];

    assign SD_ADDR_I[1:0] = ( ~NIOS_CSn && (NIOS_BE[3:0] == 4'b0001) ) ? 2'b00 : 2'bzz;

    assign SD_ADDR_I[1:0] = ( ~NIOS_CSn && (NIOS_BE[3:0] == 4'b0010) ) ? 2'b01 : 2'bzz;

    assign SD_ADDR_I[1:0] = ( ~NIOS_CSn && (NIOS_BE[3:0] == 4'b0100) ) ? 2'b10 : 2'bzz;

    assign SD_ADDR_I[1:0] = ( ~NIOS_CSn && (NIOS_BE[3:0] == 4'b1000) ) ? 2'b11 : 2'bzz;

    spiMaster SD_CNTRL_inst

    (

    .clk_i(NIOS_CLK),

    .rst_i(RESET),

    .address_i(SD_ADDR_I),

    .data_i(SD_DATA_I),

    .data_o(SD_DATA_O),

    .strobe_i(~NIOS_WRn | ~NIOS_RDn),

    .we_i(~NIOS_WRn & NIOS_RDn),

    .ack_o(NIOS_WAITREQn),

    // SPI logic clock

    .spiSysClk(SPI_CLK),

    //SPI bus

    .spiClkOut(SD_CLK),

    .spiDataIn(SD_DATA_IN),

    .spiDataOut(SD_DATA_OUT),

    .spiCS_n(SD_CS)

    );

    --- Quote End ---