一、 试验过程中发现的问题

运用ISE进行项目的完成时呈现以下过错。

意思很简单，便是运用DSP48E1的数量超出约束，因为没有触摸过DSP48E1，所以测验了许多过错的办法后，我找到项目下的.mrp文件，里边有一行显现 Number of DSP48E1s: 496 out of 480 103%，也便是说我运用的 XC6V1x130t 类型FPGA只要480个DSP48E1，可是我运用了496个。
我的项目顶用到了4个fir滤波器，都是160阶的，而且其间两个系数对称，别的两个系数不对称，我在代码中测验增加其间的某个滤波器，发现系数对称的滤波器会占用80个DSP48E1，系数不对称的fir滤波器会占用160个DSP48E1，而且结合查阅到的材料，DSP48E1首要是用来做乘法器运用的，这就十分合理了。
所以，我恰当减少了fir滤波器的系数个数，终究能够成功完成。

二、学习DSP48E1

图中带*号的信号是级联专用信号，只在级联时运用，用户逻辑拜访不了。咱们只需要重视A、B、C、D、P、INMODE、OPMODE、ALUMODE这几个信号的运用即可。

INMODE

上图首要反映了INMODE与打拍寄存器的联系，能够用下面两个表归纳，INMODE一般装备为7'b0000101，做乘法器运用。

OPMODE

X、Y、Z输出与OPMODE的联系如下表所示。

ALUMODE

终究P端口输出与ALUMODE的联系如下所示，其间的CIN便是48位输入信号C。

例程

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 2024/06/19 16:58:05
// Design Name: 
// Module Name: tb_DSP48E1
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////


module tb_DSP48E1();

    reg R_clk;
    reg R_reset;
    reg[29:0] R_A;
    reg[24:0] R_D;
    reg[47:0] R_C;
    reg[17:0] R_B;

    wire[47:0] W_P;
    wire[47:0] W_PCIN;

    reg[4:0] INMODE;
    reg[6:0] OPMODE;
    reg[3:0] ALUMODE;

    reg[3:0] R_num;

    initial begin
        R_clk = 1'b0;
        R_reset = 1'b1;
        R_A = 30'd100;
        R_B = 18'd2;
        R_C = 48'd2000;
        R_D = 25'd200;
        R_num = 4'd0;
        OPMODE = 7'b0000101;        // X-M  Y-M  Z-0
        INMODE = 5'b00101;          // (D+A1) * B2      这三个输出刚好对齐，第三拍得到运算成果
        ALUMODE = 4'b0000;          // X+Y+Z+C
        #100 R_reset = 1'b0;
    end

    always#5 R_clk = ~R_clk;

    always @(posedge R_clk) begin
        if(R_reset)begin
            R_A <= 30'd100;
            R_B <= 18'd2;
            R_C <= 48'd2000;
            R_D <= 25'd200;
            R_num <= 4'd0;
        end
        else if(R_num < 9)begin
            R_num <= R_num + 1'b1;
            R_A <= R_A + 1'b1;
            R_B <= R_B + 1'b1;
            R_C <= R_C + 1'b1;
            R_D <= R_D + 1'b1;
        end
        else begin
            OPMODE <= 7'b0110101;   // X-M  Y-M  Z-C
            R_A <= R_A + 1'b1;
            R_B <= R_B + 1'b1;
            R_C <= R_C + 1'b1;
            R_D <= R_D + 1'b1;
        end
    end

    DSP48E1 #(
      // Feature Control Attributes: Data Path Selection
      .A_INPUT("DIRECT"),               // Selects A input source, "DIRECT" (A port) or "CASCADE" (ACIN port)
      .B_INPUT("DIRECT"),               // Selects B input source, "DIRECT" (B port) or "CASCADE" (BCIN port)
      .USE_DPORT("TRUE"),              // Select D port usage (TRUE or FALSE)
      .USE_MULT("MULTIPLY"),            // Select multiplier usage ("MULTIPLY", "DYNAMIC", or "NONE")
      .USE_SIMD("ONE48"),               // SIMD selection ("ONE48", "TWO24", "FOUR12")
      // Pattern Detector Attributes: Pattern Detection Configuration
      .AUTORESET_PATDET("NO_RESET"),    // "NO_RESET", "RESET_MATCH", "RESET_NOT_MATCH" 
      .MASK(48'h3fffffffffff),          // 48-bit mask value for pattern detect (1=ignore)
      .PATTERN(48'h000000000000),       // 48-bit pattern match for pattern detect
      .SEL_MASK("MASK"),                // "C", "MASK", "ROUNDING_MODE1", "ROUNDING_MODE2" 
      .SEL_PATTERN("PATTERN"),          // Select pattern value ("PATTERN" or "C")
      .USE_PATTERN_DETECT("NO_PATDET"), // Enable pattern detect ("PATDET" or "NO_PATDET")
      // Register Control Attributes: Pipeline Register Configuration
      .ACASCREG(1),                     // Number of pipeline stages between A/ACIN and ACOUT (0, 1 or 2)
      .ADREG(1),                        // Number of pipeline stages for pre-adder (0 or 1)
      .ALUMODEREG(1),                   // Number of pipeline stages for ALUMODE (0 or 1)
      .AREG(1),                         // Number of pipeline stages for A (0, 1 or 2)
      .BCASCREG(1),                     // Number of pipeline stages between B/BCIN and BCOUT (0, 1 or 2)
      .BREG(2),                         // Number of pipeline stages for B (0, 1 or 2)                          这儿要用到B2，所以要置为2
      .CARRYINREG(1),                   // Number of pipeline stages for CARRYIN (0 or 1)
      .CARRYINSELREG(1),                // Number of pipeline stages for CARRYINSEL (0 or 1)
      .CREG(1),                         // Number of pipeline stages for C (0 or 1)
      .DREG(1),                         // Number of pipeline stages for D (0 or 1)
      .INMODEREG(1),                    // Number of pipeline stages for INMODE (0 or 1)
      .MREG(1),                         // Number of multiplier pipeline stages (0 or 1)
      .OPMODEREG(1),                    // Number of pipeline stages for OPMODE (0 or 1)
      .PREG(1)                          // Number of pipeline stages for P (0 or 1)
   )
   DSP48E1_inst (
      // Cascade: 30-bit (each) output: Cascade Ports
      .ACOUT(),                   // 30-bit output: A port cascade output
      .BCOUT(),                   // 18-bit output: B port cascade output
      .CARRYCASCOUT(),     // 1-bit output: Cascade carry output
      .MULTSIGNOUT(),       // 1-bit output: Multiplier sign cascade output
      .PCOUT(),                   // 48-bit output: Cascade output
      // Control: 1-bit (each) output: Control Inputs/Status Bits
      .OVERFLOW(),             // 1-bit output: Overflow in add/acc output
      .PATTERNBDETECT(), // 1-bit output: Pattern bar detect output
      .PATTERNDETECT(),   // 1-bit output: Pattern detect output
      .UNDERFLOW(),           // 1-bit output: Underflow in add/acc output
      // Data: 4-bit (each) output: Data Ports
      .CARRYOUT(),             // 4-bit output: Carry output
      .P(W_P),                           // 48-bit output: Primary data output
      // Cascade: 30-bit (each) input: Cascade Ports
      .ACIN(1'b0),                     // 30-bit input: A cascade data input
      .BCIN(1'b0),                     // 18-bit input: B cascade input
      .CARRYCASCIN(1'b1),       // 1-bit input: Cascade carry input
      .MULTSIGNIN(1'b1),         // 1-bit input: Multiplier sign input
      .PCIN(W_PCIN),                     // 48-bit input: P cascade input
      // Control: 4-bit (each) input: Control Inputs/Status Bits
      .ALUMODE(ALUMODE),               // 4-bit input: ALU control input
      .CARRYINSEL(3'd0),         // 3-bit input: Carry select input
      .CLK(R_clk),                       // 1-bit input: Clock input
      .INMODE(INMODE),                 // 5-bit input: INMODE control input
      .OPMODE(OPMODE),                 // 7-bit input: Operation mode input
      // Data: 30-bit (each) input: Data Ports
      .A(R_A),                           // 30-bit input: A data input
      .B(R_B),                           // 18-bit input: B data input
      .C(R_C),                           // 48-bit input: C data input
      .CARRYIN(1'b0),               // 1-bit input: Carry input signal
      .D(R_D),                           // 25-bit input: D data input
      // Reset/Clock Enable: 1-bit (each) input: Reset/Clock Enable Inputs
      .CEA1(1'b1),                     // 1-bit input: Clock enable input for 1st stage AREG
      .CEA2(1'b1),                     // 1-bit input: Clock enable input for 2nd stage AREG
      .CEAD(1'b1),                     // 1-bit input: Clock enable input for ADREG
      .CEALUMODE(1'b1),           // 1-bit input: Clock enable input for ALUMODE
      .CEB1(1'b1),                     // 1-bit input: Clock enable input for 1st stage BREG
      .CEB2(1'b1),                     // 1-bit input: Clock enable input for 2nd stage BREG
      .CEC(1'b1),                       // 1-bit input: Clock enable input for CREG
      .CECARRYIN(1'b1),           // 1-bit input: Clock enable input for CARRYINREG
      .CECTRL(1'b1),                 // 1-bit input: Clock enable input for OPMODEREG and CARRYINSELREG
      .CED(1'b1),                       // 1-bit input: Clock enable input for DREG
      .CEINMODE(1'b1),             // 1-bit input: Clock enable input for INMODEREG
      .CEM(1'b1),                       // 1-bit input: Clock enable input for MREG
      .CEP(1'b1),                       // 1-bit input: Clock enable input for PREG

      .RSTA(R_reset),                     // 1-bit input: Reset input for AREG
      .RSTALLCARRYIN(R_reset),   // 1-bit input: Reset input for CARRYINREG
      .RSTALUMODE(R_reset),         // 1-bit input: Reset input for ALUMODEREG
      .RSTB(R_reset),                     // 1-bit input: Reset input for BREG
      .RSTC(R_reset),                     // 1-bit input: Reset input for CREG
      .RSTCTRL(R_reset),               // 1-bit input: Reset input for OPMODEREG and CARRYINSELREG
      .RSTD(R_reset),                     // 1-bit input: Reset input for DREG and ADREG
      .RSTINMODE(R_reset),           // 1-bit input: Reset input for INMODEREG
      .RSTM(R_reset),                     // 1-bit input: Reset input for MREG
      .RSTP(R_reset)                      // 1-bit input: Reset input for PREG
   );
endmodule

运转成果如下图所示。

从DSP48E1结构图也能看出，终究输出成果P会在A、B、C、D输入的第四拍输出，而且C与A、B、D相差两拍，OPMODE也会推迟一拍装备进去，所以改动OPMODE之后，成果会是5170 = （108+208）* 10 + 2010，输出成果契合预期。
依照代码中的装备，X = M，Y=M，理论上加起来应该是2M，但实践便是M，这儿应该是乘法器分两部分进行乘法操作，所以最终X+Y = M。

运用DSP48E1完成fir的卷积功用

主程序如下

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 2024/06/22 11:15:16
// Design Name: 
// Module Name: pck_fir
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////

// 运用dsp48e1完成fir滤波器
// 先串行输入滤波器系数，假定 x = [1,2...11]
// 再串行输入信号，假定 t = [31,32...1000]
// 最终得到成果为 y = conv(x,t)
module pck_fir # (
    parameter C_COE_WIDTH = 16,
    parameter C_INPUT_WIDTH = 16,
    parameter C_OUTPUT_WIDTH = 48,
    parameter C_COE_NUM = 11
)
(
    input I_clk,
    input I_rst,
    input I_coe_param_vd,
    input[C_COE_WIDTH-1:0] I_coe_param,
    input I_data_vd,
    input[C_INPUT_WIDTH-1:0] I_data,
    output[C_OUTPUT_WIDTH-1:0] O_data
);

localparam C_A_WIDTH = 30;
localparam C_B_WIDTH = 18;
localparam C_C_WIDTH = 48;
localparam C_D_WIDTH = 25;
localparam C_P_WIDTH = 48;

reg[C_B_WIDTH-1:0] R_coe_params[C_COE_NUM-1:0];
reg[C_A_WIDTH-1:0] R_data;

wire[47:0] W_cin;
wire[24:0] W_din;
wire[47:0] W_pin;
wire[47:0] W_pout[C_COE_NUM-1:0];

assign W_cin = 48'd0;
assign W_din = 25'd0;
assign W_pin = 48'd0;

always @(posedge I_clk or negedge I_rst) begin
    if(~I_rst)begin
        R_data <= 'd0;
    end
    else if(I_data_vd)begin
        R_data[C_INPUT_WIDTH-1:0] <= I_data;
    end
    else
        R_data <= 0;
end

genvar i;
generate
    for(i = 0;i < C_COE_NUM;i = i + 1)
    begin
        always @(posedge I_clk or negedge I_rst) begin
            if(~I_rst)begin
                R_coe_params[i] <= 'd0;
            end
            else begin
                if(I_coe_param_vd)begin
                    if(i == 0)
                        R_coe_params[i][C_COE_WIDTH-1:0] <= I_coe_param;
                    else
                        R_coe_params[i] <= R_coe_params[i-1]; 
                end
                else
                    R_coe_params[i] <= R_coe_params[i];
            end
        end
    end
endgenerate

pck_dsp48e1 pck_1(
    .I_clk(I_clk),
    .I_rst(~I_rst),
    .A(R_data),
    .B(R_coe_params[0]),
    .C(W_cin),
    .D(W_din),
    .PCIN(W_pin),
    .P(),
    .PCOUT(W_pout[0])
);

genvar k;
generate
    for(k = 1;k < C_COE_NUM;k = k + 1)
    begin:dsp_gen
        pck_dsp48e1 #(
            .C_OPMODE(7'b0010101)
        ) pck_n(
            .I_clk(I_clk),
            .I_rst(~I_rst),
            .A(R_data),
            .B(R_coe_params[k]),
            .C(W_cin),
            .D(W_din),
            .PCIN(W_pout[k-1]),
            .P(),
            .PCOUT(W_pout[k])
        );
    end
endgenerate

assign O_data = W_pout[C_COE_NUM-1];

endmodule

因为DSP48E1参数较多，能够进行恰当封装，封装后如下。

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 2024/06/22 10:45:31
// Design Name: 
// Module Name: pck_dsp48e1
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////


module pck_dsp48e1 # (
    parameter C_ALUMODE = 4'b0000,
    parameter C_INMODE = 5'b00101,
    parameter C_OPMODE = 7'b0000101
)
(
    input I_clk,
    input I_rst,
    input[29:0] A,
    input[17:0] B,
    input[47:0] C,
    input[24:0] D,
    input[47:0] PCIN,
    output[47:0] P,
    output[47:0] PCOUT
);

    DSP48E1 #(
      // Feature Control Attributes: Data Path Selection
      .A_INPUT("DIRECT"),               // Selects A input source, "DIRECT" (A port) or "CASCADE" (ACIN port)
      .B_INPUT("DIRECT"),               // Selects B input source, "DIRECT" (B port) or "CASCADE" (BCIN port)
      .USE_DPORT("TRUE"),              // Select D port usage (TRUE or FALSE)
      .USE_MULT("MULTIPLY"),            // Select multiplier usage ("MULTIPLY", "DYNAMIC", or "NONE")
      .USE_SIMD("ONE48"),               // SIMD selection ("ONE48", "TWO24", "FOUR12")
      // Pattern Detector Attributes: Pattern Detection Configuration
      .AUTORESET_PATDET("NO_RESET"),    // "NO_RESET", "RESET_MATCH", "RESET_NOT_MATCH" 
      .MASK(48'h3fffffffffff),          // 48-bit mask value for pattern detect (1=ignore)
      .PATTERN(48'h000000000000),       // 48-bit pattern match for pattern detect
      .SEL_MASK("MASK"),                // "C", "MASK", "ROUNDING_MODE1", "ROUNDING_MODE2" 
      .SEL_PATTERN("PATTERN"),          // Select pattern value ("PATTERN" or "C")
      .USE_PATTERN_DETECT("NO_PATDET"), // Enable pattern detect ("PATDET" or "NO_PATDET")
      // Register Control Attributes: Pipeline Register Configuration
      .ACASCREG(1),                     // Number of pipeline stages between A/ACIN and ACOUT (0, 1 or 2)
      .ADREG(1),                        // Number of pipeline stages for pre-adder (0 or 1)
      .ALUMODEREG(1),                   // Number of pipeline stages for ALUMODE (0 or 1)
      .AREG(1),                         // Number of pipeline stages for A (0, 1 or 2)
      .BCASCREG(1),                     // Number of pipeline stages between B/BCIN and BCOUT (0, 1 or 2)
      .BREG(2),                         // Number of pipeline stages for B (0, 1 or 2)                          这儿要用到B2，所以要置为2
      .CARRYINREG(1),                   // Number of pipeline stages for CARRYIN (0 or 1)
      .CARRYINSELREG(1),                // Number of pipeline stages for CARRYINSEL (0 or 1)
      .CREG(1),                         // Number of pipeline stages for C (0 or 1)
      .DREG(1),                         // Number of pipeline stages for D (0 or 1)
      .INMODEREG(1),                    // Number of pipeline stages for INMODE (0 or 1)
      .MREG(1),                         // Number of multiplier pipeline stages (0 or 1)
      .OPMODEREG(1),                    // Number of pipeline stages for OPMODE (0 or 1)
      .PREG(1)                          // Number of pipeline stages for P (0 or 1)
   )
   DSP48E1_inst (
      // Cascade: 30-bit (each) output: Cascade Ports
      .ACOUT(),                   // 30-bit output: A port cascade output
      .BCOUT(),                   // 18-bit output: B port cascade output
      .CARRYCASCOUT(),     // 1-bit output: Cascade carry output
      .MULTSIGNOUT(),       // 1-bit output: Multiplier sign cascade output
      .PCOUT(PCOUT),                   // 48-bit output: Cascade output
      // Control: 1-bit (each) output: Control Inputs/Status Bits
      .OVERFLOW(),             // 1-bit output: Overflow in add/acc output
      .PATTERNBDETECT(), // 1-bit output: Pattern bar detect output
      .PATTERNDETECT(),   // 1-bit output: Pattern detect output
      .UNDERFLOW(),           // 1-bit output: Underflow in add/acc output
      // Data: 4-bit (each) output: Data Ports
      .CARRYOUT(),             // 4-bit output: Carry output
      .P(P),                           // 48-bit output: Primary data output
      // Cascade: 30-bit (each) input: Cascade Ports
      .ACIN(1'b0),                     // 30-bit input: A cascade data input
      .BCIN(1'b0),                     // 18-bit input: B cascade input
      .CARRYCASCIN(1'b1),       // 1-bit input: Cascade carry input
      .MULTSIGNIN(1'b1),         // 1-bit input: Multiplier sign input
      .PCIN(PCIN),                     // 48-bit input: P cascade input
      // Control: 4-bit (each) input: Control Inputs/Status Bits
      .ALUMODE(C_ALUMODE),               // 4-bit input: ALU control input
      .CARRYINSEL(3'd0),         // 3-bit input: Carry select input
      .CLK(I_clk),                       // 1-bit input: Clock input
      .INMODE(C_INMODE),                 // 5-bit input: INMODE control input
      .OPMODE(C_OPMODE),                 // 7-bit input: Operation mode input
      // Data: 30-bit (each) input: Data Ports
      .A(A),                           // 30-bit input: A data input
      .B(B),                           // 18-bit input: B data input
      .C(C),                           // 48-bit input: C data input
      .CARRYIN(1'b0),               // 1-bit input: Carry input signal
      .D(D),                           // 25-bit input: D data input
      // Reset/Clock Enable: 1-bit (each) input: Reset/Clock Enable Inputs
      .CEA1(1'b1),                     // 1-bit input: Clock enable input for 1st stage AREG
      .CEA2(1'b1),                     // 1-bit input: Clock enable input for 2nd stage AREG
      .CEAD(1'b1),                     // 1-bit input: Clock enable input for ADREG
      .CEALUMODE(1'b1),           // 1-bit input: Clock enable input for ALUMODE
      .CEB1(1'b1),