FPGA 204B實(shí)戰(zhàn)應(yīng)用-LMK04821代碼詳解

大俠好，歡迎來到FPGA技術(shù)江湖，江湖偌大，相見即是緣分。大俠可以關(guān)注FPGA技術(shù)江湖，在“闖蕩江湖”、"行俠仗義"欄里獲取其他感興趣的資源，或者一起煮酒言歡。“煮酒言歡”進(jìn)入IC技術(shù)圈，這里有近50個(gè)IC技術(shù)公眾號(hào)。

大俠好，阿Q來也，今天是第二次和各位見面，請(qǐng)各位大俠多多關(guān)照。今天給各位大俠帶來一篇項(xiàng)目開發(fā)經(jīng)驗(yàn)分享“基于JESD204B的LMK04821芯片項(xiàng)目開發(fā)”第二篇，這是本人實(shí)打?qū)嵉捻?xiàng)目開發(fā)經(jīng)驗(yàn)，希望可以給有需要的大俠提供一些參考學(xué)習(xí)作用。

以后機(jī)會(huì)多多，慢慢分享一些項(xiàng)目開發(fā)以及學(xué)習(xí)方面的內(nèi)容，歡迎各位大俠一起切磋交流。也歡迎進(jìn)群交流，文章末尾有進(jìn)群方式。話不多說，上貨。

204B實(shí)戰(zhàn)應(yīng)用-LMK04821代碼詳解（二）

一、?SPI協(xié)議

通過閱讀LMK04821數(shù)據(jù)手冊(cè)，我們可以從中知道，可以通過SPI協(xié)議對(duì)LMK04821進(jìn)行寄存器的配置工作，進(jìn)而實(shí)現(xiàn)我們?cè)O(shè)計(jì)所需要的功能。

SPI協(xié)議部分，咱們可以用3線，或者4線，在本次設(shè)計(jì)中，使用3線。關(guān)于SPI的時(shí)序部分，這兒就不再贅述，手冊(cè)里面都有詳細(xì)的描述。

圖1

二、?SPI寄存器配置模塊設(shè)計(jì)

圖2

如圖2所示，就是配置LMK04821存器的單元，信號(hào)定義如下：

1、cfg_clk：系統(tǒng)時(shí)鐘；

2、cfg_rst：系統(tǒng)復(fù)位；

3、通過VIO控制的信號(hào)，這組信號(hào)存在的目的在于方便檢測(cè)自己配置寄存器的正確性。

vio_cfg_en：配置寄存器使能信號(hào)；

vio_cfg_wr：配置寄存器讀寫使能，0寫1讀；

vio_cfg_addr：配置的寄存器地址；

vio_cfg_wdata：寄存器中配置的值；

addr_118_data：預(yù)留信號(hào)，模塊中沒有用；

我們?cè)谂渲肔MK04821寄存器時(shí)，要驗(yàn)證配置寄存器操作是否正確，就要有寫有讀，在對(duì)應(yīng)的寄存器內(nèi)寫入對(duì)應(yīng)的數(shù)值，然后進(jìn)行讀操作，觀察正確性。本次設(shè)計(jì)是在vivado環(huán)境下進(jìn)行設(shè)計(jì)，通過添加VIO的IP核，來控制讀寫操作。同時(shí)，添加ILA配合VIO來進(jìn)行讀寫數(shù)據(jù)操作的觀測(cè)。別的開發(fā)環(huán)境下思路一樣。

該組信號(hào)僅在回讀寄存器時(shí)使用，目的是為了驗(yàn)證寄存器讀寫正確性。

圖3

4、lmk_rst：LMK04821復(fù)位信號(hào)，用于復(fù)位LMK04821，直接和LMK04821芯片相連；

5、3線制SPI信號(hào)：

lmk_spi_csn：片選；

lmk_spi_sdio：數(shù)據(jù)；

lmk_spi_clk：時(shí)鐘；

6、可編程管教：主要和LMK04821內(nèi)部的PLL相關(guān)，本次設(shè)計(jì)中默認(rèn)為0；

lmk_clk_sel0 ：sel0；

lmk_clk_sel1 ：sel1；

三、?SPI數(shù)據(jù)buffer定義

在本次設(shè)計(jì)中，SPI配置數(shù)據(jù)buffer，data_reg為24bit，r_w占1bit，箭頭1所指包含W1、W2以及地址位占13bit，具體見SPI時(shí)序圖；箭頭2所指數(shù)據(jù)位8bit。

圖4

根據(jù)圖5我們可以知道，要配置LMK04821我們需要配置126個(gè)寄存器，這126個(gè)寄存器來源參見第一章實(shí)戰(zhàn)記錄。

其中，126個(gè)寄存器包含必須要配的寄存器、一些無關(guān)緊要的寄存器、以及功能實(shí)現(xiàn)所需要的寄存器等，有些寄存器需要配置多次。

圖5

四、?SPI時(shí)序?qū)崿F(xiàn)

設(shè)計(jì)中，我們需要按照順序配置126個(gè)寄存器，也就是說SPI要執(zhí)行126次。因此，在代碼實(shí)現(xiàn)過程中，注意寄存器配置的順序，并且保證每個(gè)寄存器都準(zhǔn)確無誤的配置完成，才能進(jìn)行下一個(gè)寄存器的配置。如果在設(shè)計(jì)中，要求LMK004821實(shí)現(xiàn)不同的功能，當(dāng)配置的寄存器個(gè)數(shù)不一致時(shí)，在v文件中更改圖6所示的參數(shù)即可。

圖6

如下：是LMK04821配置的模塊，讀者可以作為參考。

代碼區(qū)（參考代碼）：

//###########################################################################//// Copyright (C) 2017, JSZX, Co. Ltd. All Rights Reserved.//###########################################################################////-- Project Name ://-- File Name    :  lmk04821_spi//-- Description  ://###########################################################################////---------------------------Modification History----------------------------////-- Date        By            Ver   Comment//-- 12/04/2017  hhh           1.0   Create new//===================================================================//-- End Revision//===================================================================`timescale 1ns / 1ps
module lmk04821_spi(    input            cfg_clk               , //<=10MHz    input            cfg_rst               ,    input            vio_cfg_en            ,    input            vio_cfg_wr            ,//0,write;1,read;    input [12:0]     vio_cfg_addr          ,    input [07:0]     vio_cfg_wdata         ,    input [07:0]     addr_118_data         ,
    input            r_w                   ,    input            lmk_cfgen             ,    output           lmk_rst               ,    output           lmk_spi_csn           ,    inout  tri       lmk_spi_sdio          ,    output           lmk_spi_clk           ,    output           lmk_clk_sel0          ,    output           lmk_clk_sel1          ,    output reg       regdatareadvalid      ,    output reg [7:0] regdataread           ,    output reg       lmk_cfgdone = 1'b0    );    //parameter defination    parameter   NUM_REG      = 8'd126      ;//需要配置的寄存器個(gè)數(shù)    parameter   CFG_DONE_DLY = 32'hF4240   ;//100ms@10Mhz;    //====================================================================//    //----------------------internal signals------------------------------//    //====================================================================//    reg [00:0]  lmk_cfgen_d0               ;    reg [00:0]  lmk_cfgen_d1               ;    reg [00:0]  lmk_cfgen_d2               ;    reg [00:0]  vio_cfg_en_d0              ;    reg [00:0]  vio_cfg_en_d1              ;    reg [00:0]  vio_cfg_en_d2              ;    reg [07:0]  cnt_clk                    ;// 每個(gè)寄存器需要的時(shí)鐘數(shù)計(jì)數(shù)器    reg [07:0]  cnt_reg                    ;// 需要配置的寄存器計(jì)數(shù)器,最多255個(gè)!    reg [23:0]  data_reg                   ;    reg [00:0]  load_p                     ;    reg [00:0]  load_p_d0                  ;    reg [35:0]  mid_data_o                 ;    reg [35:0]  mid_csn_o                  ;    reg [00:0]  spi_sdo                    ;    reg [00:0]  spi_cs_n                   ;    wire[00:0]  spi_sdi                    ;    reg [05:0]  sdo_cnt                    ;//    //====================================================================////    //-----------------------------ila debug------------------------------////    //====================================================================////    //ila_spi//    ila_spi ila_spi(//    .clk        ( cfg_clk             ),////    .probe0     ( cnt_clk             ),//8//    .probe1     ( cnt_reg             ),//8//    .probe2     ( data_reg            ),//24//    .probe3     ( load_p              ),//1//    .probe4     ( sdo_cnt             ),//6//    .probe5     ( spi_cs_n            ),//1//    .probe6     ( spi_sdi             ),//1//    .probe7     ( spi_sdo             ),//1//    .probe8     ( lmk_cfgen_d1        ) //1//    );    //====================================================================//    //--------------------------main process------------------------------//    //====================================================================//    //lmk_clk_sel    assign      lmk_clk_sel0= 1'b0 ;    assign      lmk_clk_sel1= 1'b0 ;    //spi signals;    assign      lmk_rst     = cfg_rst    ;    assign      lmk_spi_clk = (spi_cs_n) ? 1'b0 : ~cfg_clk    ;    assign      lmk_spi_csn = spi_cs_n    ;    assign      spi_sdi     = lmk_spi_sdio;    assign      lmk_spi_sdio= (data_reg[23]==1'b1 && sdo_cnt>6'h18)? 1'bz : spi_sdo ;    //lmk_cfgen_d0/lmk_cfgen_d1/lmk_cfgen_d2/load_p_d0    always @(posedge cfg_clk or posedge cfg_rst)    begin        if(cfg_rst==1'b1)        begin            lmk_cfgen_d0 <= 1'b0 ;            lmk_cfgen_d1 <= 1'b0 ;            lmk_cfgen_d2 <= 1'b0 ;            load_p_d0    <= 1'b0 ;            vio_cfg_en_d0 <= 1'b0 ;            vio_cfg_en_d1 <= 1'b0 ;            vio_cfg_en_d2 <= 1'b0 ;        end        else        begin            lmk_cfgen_d0 <= lmk_cfgen ;            lmk_cfgen_d1 <= lmk_cfgen_d0 ;            lmk_cfgen_d2 <= lmk_cfgen_d1 ;            load_p_d0    <= load_p ;            vio_cfg_en_d0 <= vio_cfg_en ;            vio_cfg_en_d1 <= vio_cfg_en_d0 ;            vio_cfg_en_d2 <= vio_cfg_en_d1 ;        end    end    //load_p/cnt_reg/cnt_clk    always @(posedge cfg_clk or posedge cfg_rst)    begin        if(cfg_rst==1'b1)        begin            cnt_reg <= 8'd0  ;            cnt_clk <= 8'd36 ;            load_p  <= 1'b0  ;        end        else        begin            if(lmk_cfgen_d1==1'b1 && lmk_cfgen_d2==1'b0)            begin                cnt_clk <= 8'd0 ;                cnt_reg <= 8'd0  ;                load_p  <= 1'b0 ;            end            else if((cnt_clk==8'd36)&&(cnt_reg<NUM_REG))            begin                cnt_clk <= 8'd0 ;                cnt_reg <= cnt_reg + 8'h1 ;                load_p  <= 1'b1 ;            end            else            begin                load_p  <= 1'b0 ;                if(cnt_clk==8'd36)//cnt_reg==NUM_REG                begin                    cnt_clk <= 8'd0 ;                    cnt_reg <= cnt_reg ;                end                else                begin                    cnt_clk <= cnt_clk + 8'h1 ;                    cnt_reg <= cnt_reg ;                end            end        end    end    //data_reg:VCO0,1930~2075;VCO1,2920~3080;    always @(posedge cfg_clk or posedge cfg_rst)    begin        if(cfg_rst==1'b1)        begin            data_reg <= 24'h80_0000;        end        else        begin            case(cnt_reg)//VCO_2Ghz;                // Serial Port Configuration                8'd1     : data_reg <= {r_w,23'h0000_80} ;//soft reset                8'd2     : data_reg <= {r_w,23'h0000_00} ;//
                8'd3     : data_reg <= {r_w,23'h0100_04} ;//500Mhz;DCLKout0: input and output drive level;device clock out divider values                8'd4     : data_reg <= {r_w,23'h0101_55} ;//controls the digital delay high and low count values for the device clock outputs                8'd5     : data_reg <= {r_w,23'h0103_00} ;//registers control the analog delay properties for the device clocks                8'd6     : data_reg <= {r_w,23'h0104_22} ;//set the half step for the device clock, the SYSREF output MUX, the SYSREF clock digital delay,and half step                8'd7     : data_reg <= {r_w,23'h0105_00} ;//set the analog delay parameters for the SYSREF outputs                8'd8     : data_reg <= {r_w,23'h0106_70} ;//controls the power down functions for the digital delay, glitchless half step                8'd9     : data_reg <= {r_w,23'h0107_15} ;//configure the output polarity, and format:11:LVDS;15:LVPECL16;                8'd10    : data_reg <= {r_w,23'h0108_10} ;//125Mhz;DCLKout2;V7_IO_CLK2;                8'd11    : data_reg <= {r_w,23'h0109_55} ;                8'd12    : data_reg <= {r_w,23'h010B_00} ;                8'd13    : data_reg <= {r_w,23'h010C_22} ;//bit[5]:SDCLKoutY_MUX;0, Device clock output;                8'd14    : data_reg <= {r_w,23'h010D_00} ;                8'd15    : data_reg <= {r_w,23'h010E_70} ;//bit[3]:0,enable;bit[4]:powerdown;                8'd16    : data_reg <= {r_w,23'h010F_11} ;//11:LVDS;15:LVPECL16                8'd17    : data_reg <= {r_w,23'h0110_10} ;//125Mhz;DCLKout4;                8'd18    : data_reg <= {r_w,23'h0111_55} ;                8'd19    : data_reg <= {r_w,23'h0113_00} ;                8'd20    : data_reg <= {r_w,23'h0114_22} ;//bit[5]:SDCLKoutY_MUX;0, Device clock output;                8'd21    : data_reg <= {r_w,23'h0115_00} ;                8'd22    : data_reg <= {r_w,23'h0116_70} ;//bit[3]:0,enable;bit[4]:powerdown;                8'd23    : data_reg <= {r_w,23'h0117_11} ;//11:LVDS;15:LVPECL16                8'd24    : data_reg <= {r_w,23'h0118_04} ;//500Mhz;DCLKout6,FPGA;V7_IO_CLK0;                8'd25    : data_reg <= {r_w,23'h0119_55} ;                8'd26    : data_reg <= {r_w,23'h011B_00} ;                8'd27    : data_reg <= {r_w,23'h011C_22} ;//bit[5]:SDCLKoutY_MUX;0, Device clock output;                8'd28    : data_reg <= {r_w,23'h011D_00} ;                8'd29    : data_reg <= {r_w,23'h011E_70} ;                8'd30    : data_reg <= {r_w,23'h011F_11} ;//11:LVDS;15:LVPECL16                8'd31    : data_reg <= {r_w,23'h0120_10} ;//125Mhz;DCLKout8,FPGA MGT114 CLOCK;                8'd32    : data_reg <= {r_w,23'h0121_55} ;                8'd33    : data_reg <= {r_w,23'h0123_00} ;                8'd34    : data_reg <= {r_w,23'h0124_02} ;//bit[5]:SDCLKoutY_MUX;0, Device clock output;                8'd35    : data_reg <= {r_w,23'h0125_00} ;                8'd36    : data_reg <= {r_w,23'h0126_70} ;                8'd37    : data_reg <= {r_w,23'h0127_11} ;//11:LVDS;15:LVPECL16                8'd38    : data_reg <= {r_w,23'h0128_10} ;//125Mhz;DCLKout10,FPGA MGT116 CLOCK;                8'd39    : data_reg <= {r_w,23'h0129_55} ;                8'd40    : data_reg <= {r_w,23'h012B_00} ;                8'd41    : data_reg <= {r_w,23'h012C_02} ;//bit[5]:SDCLKoutY_MUX;0, Device clock output;                8'd42    : data_reg <= {r_w,23'h012D_00} ;                8'd43    : data_reg <= {r_w,23'h012E_70} ;                8'd44    : data_reg <= {r_w,23'h012F_11} ;//11:LVDS;15:LVPECL16                8'd45    : data_reg <= {r_w,23'h0130_04} ;//500Mhz;DCLKout12;                8'd46    : data_reg <= {r_w,23'h0131_55} ;                8'd47    : data_reg <= {r_w,23'h0133_00} ;                8'd48    : data_reg <= {r_w,23'h0134_22} ;                8'd49    : data_reg <= {r_w,23'h0135_00} ;                8'd50    : data_reg <= {r_w,23'h0136_70} ;                8'd51    : data_reg <= {r_w,23'h0137_15} ;//11:LVDS;15:LVPECL16
                8'd52    : data_reg <= {r_w,23'h0138_00} ;//selects the clock distribution source, and OSCout parameters;VCO0;                8'd53    : data_reg <= {r_w,23'h0139_03} ;//sets the source for the SYSREF outputs                8'd54    : data_reg <= {r_w,23'h013A_00} ;//SYSREF_DIV[12:8] DIV register 1;sysref 2000M/160=12.5Mhz;                8'd55    : data_reg <= {r_w,23'h013B_A0} ;//SYSREF_DIV[7:0] DIV register 0;                8'd56    : data_reg <= {r_w,23'h013C_08} ;//set the delay of the SYSREF digital delay value[12:8]                8'd57    : data_reg <= {r_w,23'h013D_00} ;//set the delay of the SYSREF digital delay value[7:0]                8'd58    : data_reg <= {r_w,23'h013E_03} ;//sets the number of SYSREF pulses if SYSREF is not in continuous mode;
                8'd59    : data_reg <= {r_w,23'h013F_04} ;//controls the feedback feature                8'd60    : data_reg <= {r_w,23'h0140_01} ;//13-OSCin PD; powerdown controls for OSCin and SYSREF functions;bit[0]:Powerdown SYSREF pulse generator;                8'd61    : data_reg <= {r_w,23'h0141_FF} ;//enables dynamic digital delay for enabled device clocks                8'd62    : data_reg <= {r_w,23'h0142_00} ;//sets the number of dynamic digital delay adjustments occur                8'd63    : data_reg <= {r_w,23'h0143_91} ;//sets general SYNC parameters such as polarization, and mode                8'd64    : data_reg <= {r_w,23'h0144_00} ;//prevent a clock output from being synchronized or interrupted by a SYNC event or when outputting SYSREF                8'd65    : data_reg <= {r_w,23'h0145_7F} ;//Always program this register to value 127                8'd66    : data_reg <= {r_w,23'h0171_AA} ;//                8'd67    : data_reg <= {r_w,23'h0172_02} ;//                8'd68    : data_reg <= {r_w,23'h0173_00} ;//bit[6]PLL2_PRE_PD; bit[5]PLL2_PD;                8'd70    : data_reg <= {r_w,23'h017C_15} ;//OPT_REG_1:21;                8'd71    : data_reg <= {r_w,23'h017D_33} ;//OPT_REG_2:51;                8'd72    : data_reg <= {r_w,23'h0182_00} ;                8'd73    : data_reg <= {r_w,23'h0183_00} ;                8'd74    : data_reg <= {r_w,23'h0184_00} ;                8'd75    : data_reg <= {r_w,23'h0185_00} ;                8'd76    : data_reg <= {r_w,23'h0188_00} ;
                8'd77    : data_reg <= {r_w,23'h0146_38} ;//CLKin enable and type controls.                8'd78    : data_reg <= {r_w,23'h0147_02} ;//CLKin_SEL_MODE. pin select mode;                8'd79    : data_reg <= {r_w,23'h0148_02} ;//CLKin_SEL0 controls                8'd80    : data_reg <= {r_w,23'h0149_42} ;//CLKin_SEL1 controls and register readback SDIO pin type                8'd81    : data_reg <= {r_w,23'h014A_02} ;//contains control of the RESET pin                8'd82    : data_reg <= {r_w,23'h014B_16} ;//contains the holdover functions:start;                8'd83    : data_reg <= {r_w,23'h014C_00} ;//                8'd84    : data_reg <= {r_w,23'h014D_00} ;//                8'd85    : data_reg <= {r_w,23'h014E_C0} ;//                8'd86    : data_reg <= {r_w,23'h014F_7F} ;//                8'd87    : data_reg <= {r_w,23'h0150_03} ;//                8'd88    : data_reg <= {r_w,23'h0151_02} ;//                8'd89    : data_reg <= {r_w,23'h0152_00} ;//contains the holdover functions:end;                8'd90    : data_reg <= {r_w,23'h0153_00} ;//CLKin0_R[13:8]                8'd91    : data_reg <= {r_w,23'h0154_01} ;//CLKin0_R[7:0]                8'd92    : data_reg <= {r_w,23'h0155_00} ;//CLKin1_R[13:8]                8'd93    : data_reg <= {r_w,23'h0156_40} ;//CLKin1_R[7:0]                8'd94    : data_reg <= {r_w,23'h0157_00} ;//CLKin2_R[13:8]                8'd95    : data_reg <= {r_w,23'h0158_40} ;//CLKin2_R[7:0]                8'd96    : data_reg <= {r_w,23'h0159_00} ;//PLL1_N[13:8]                8'd97    : data_reg <= {r_w,23'h015A_01} ;//PLL1_N[7:0]                8'd98    : data_reg <= {r_w,23'h015B_D4} ;//PLL1 phase detector                8'd99    : data_reg <= {r_w,23'h015C_20} ;//PLL1_DLD_CNT[13:8]                8'd100   : data_reg <= {r_w,23'h015D_00} ;//PLL1_DLD_CNT[7:0]                8'd101   : data_reg <= {r_w,23'h015E_00} ;//contains the delay value for PLL1 N and R delays.                8'd102   : data_reg <= {r_w,23'h015F_0B} ;//configures the PLL1 LD pin                8'd103   : data_reg <= {r_w,23'h0160_00} ;//PLL2_R[11:8]                8'd104   : data_reg <= {r_w,23'h0161_01} ;//PLL2_R[7:0]                8'd105   : data_reg <= {r_w,23'h0162_44} ;//sets other PLL2 functions:[7:5]:PLL2_P;[4:2]:OSCin_FREQ;[1]:PLL2_XTAL_EN;[0]:PLL2_REF_2X_EN;                8'd106   : data_reg <= {r_w,23'h0163_00} ;//PLL2_N_CAL[17:16]                8'd107   : data_reg <= {r_w,23'h0164_00} ;//PLL2_N_CAL[15:8]                8'd108   : data_reg <= {r_w,23'h0165_0C} ;//PLL2_N_CAL[7:0]                8'd109   : data_reg <= {r_w,23'h0166_00} ;//PLL2_N[17:16],MSB;                8'd110   : data_reg <= {r_w,23'h0167_00} ;//PLL2_N[15:8],---;                8'd111   : data_reg <= {r_w,23'h0168_0A} ;//PLL2_N[7:0],LSB;                8'd112   : data_reg <= {r_w,23'h0169_59} ;//controls the PLL2 phase detector                8'd113   : data_reg <= {r_w,23'h016A_60} ;//                8'd114   : data_reg <= {r_w,23'h016B_00} ;//                8'd115   : data_reg <= {r_w,23'h016C_00} ;//                8'd116   : data_reg <= {r_w,23'h016D_00} ;//                8'd117   : data_reg <= {r_w,23'h016E_13} ;//                8'd118   : data_reg <= {r_w,23'h0143_90} ;//                8'd119   : data_reg <= {r_w,23'h0139_00} ;//                8'd120   : data_reg <= {r_w,23'h0143_B0} ;//                8'd121   : data_reg <= {r_w,23'h0143_90} ;//                8'd122   : data_reg <= {r_w,23'h0144_FF} ;//                8'd123   : data_reg <= {r_w,23'h0143_10} ;//                8'd124   : data_reg <= {r_w,23'h0143_11} ;//                8'd125   : data_reg <= {r_w,23'h0139_03} ;//                8'd126   : data_reg <= {1'b1,23'h0002_00} ;//                default  : data_reg <= 24'h80_0000  ;            endcase        end    end    //spi_sdo/spi_cs_n/mid_data_o/mid_csn_o/mid_data_o/vio_cfg_cnt    always @(posedge cfg_clk or posedge cfg_rst)    begin        if(cfg_rst==1'b1)        begin            spi_sdo    <=  1'b0;            spi_cs_n   <=  1'b1;            mid_data_o <=  36'h0;            mid_csn_o  <=  36'hFFFFFFFFF;            sdo_cnt <= 6'b0 ;        end        else        begin            if(load_p_d0==1'b1)            begin                spi_sdo    <=  1'b0;                mid_data_o <=  {data_reg[23:0],12'hfff};//r_w:0 write;1 read;                spi_cs_n   <=  1'b1;                mid_csn_o  <=  {24'h0,12'hFFF};                sdo_cnt <= 6'h1 ;            end            else if(vio_cfg_en_d1==1'b1 && vio_cfg_en_d2==1'b0)            begin                spi_sdo    <=  1'b0;                mid_data_o <=  {vio_cfg_wr,2'b00,vio_cfg_addr,vio_cfg_wdata,12'hfff};//r_w:0 write;1 read;                spi_cs_n   <=  1'b1;                mid_csn_o  <=  {24'h0,12'hFFF};                sdo_cnt <= 6'h1 ;            end            else            begin                spi_sdo    <=  mid_data_o[35];                mid_data_o <=  {mid_data_o[34:0],1'b0};                spi_cs_n   <=  mid_csn_o[35];                mid_csn_o  <=  {mid_csn_o[34:0],1'b1};                if(sdo_cnt<6'h3f)                begin                    sdo_cnt <= sdo_cnt + 6'h1 ;                end                else                begin                    sdo_cnt <= sdo_cnt ;                end            end        end    end    //regdatareadvalid/regdataread    always @(posedge cfg_clk or posedge cfg_rst)    begin        if(cfg_rst==1'b1)        begin            regdatareadvalid <= 1'b0 ;            regdataread <= 8'b0 ;        end        else        begin            if(spi_cs_n==1'b0)            begin                if(data_reg[23]==1'b1)                begin                    if(sdo_cnt>6'd18 && sdo_cnt<6'd25)//2-17;18-25;                    begin                        regdatareadvalid <= 1'b0 ;                        regdataread <= {regdataread[6:0],spi_sdi};                    end                    else if(sdo_cnt==6'd25)                    begin                        regdatareadvalid <= 1'b1 ;                        regdataread <= {regdataread[6:0],spi_sdi};                    end                    else                    begin                        regdatareadvalid <= 1'b0 ;                        regdataread <= regdataread ;                    end                end                else                begin                    regdatareadvalid <= 1'b0 ;                    regdataread <= regdataread ;                end            end            else            begin                regdatareadvalid <= 1'b0 ;                regdataread <= regdataread ;            end        end    end    //lmk_cfgdone    always @(posedge cfg_clk or posedge cfg_rst)    begin        if(cfg_rst)        begin            lmk_cfgdone <= 1'b0 ;        end        else        begin            if(cnt_reg>=NUM_REG)            begin                lmk_cfgdone <= 1'b1 ;            end            else            begin                lmk_cfgdone <= 1'b0 ;            end        end    end    //====================================================================//    //-------------------------------  end  ------------------------------//    //====================================================================//
endmodule

下一篇，將詳細(xì)介紹jesd_204B IP核應(yīng)用的相關(guān)知識(shí)，各位大俠，盡請(qǐng)關(guān)注。