【转】基于FPGA的IIR滤波器

zada小明

基于FPGA的IIR滤波器

by方阳

1.说明
这是之前EDA做的综合大实验，拿出来和大家分享分享！
先说一下，此篇文章是基于你有IIR滤波器的原理和FPGA语言（也就是Verilog HDL）基础上的！至于IIR滤波器的原理和Verilog HDL语言，我这里就不说了，网上有一大堆的资料可以观看，IIR可以看数字信号处理的书或直接百度，Verilog HDL推荐《Hello,FPGA》!
申明一下，这边博客很长，请做好心理准备！！！
说明：这个IIR滤波器我是用芯航线FPGA开发板——cyclone IV E EP4CE10F1708实现的，还用了ADDA模块——集成TLC1544 ADC采集芯片和TLC5620 DAC 输出芯片，软件平台是quartus13.0，测试用的是信号发生器和示波器。
这个共有一个顶层文件，十一个子文件，子文件其中一个是IIR滤波器的顶层文件。拓扑图如下：

2.参考代码
相应的代码如下
2.1 顶层文件IIR_FY_TOP.V

module IIR_FY_TOP
(
Clk,
Rst_n,
TLC5620_CLK,
TLC5620_DATA,
TLC5620_LOAD,
TLC5620_LDAC,
TLV1544_SDO,
TLV1544_SDI,
TLV1544_SCLK,
TLV1544_NCS,
TLV1544_FS,
TLV1544_EOC
);
input Clk;
input Rst_n;
output TLC5620_CLK;
output TLC5620_DATA;
output TLC5620_LOAD;
output TLC5620_LDAC;
input TLV1544_SDO;
output TLV1544_SDI;
output TLV1544_SCLK;
output TLV1544_NCS;
output TLV1544_FS;
input TLV1544_EOC;
wire AD_DONE;
wire [9:0]ADC_DATA;
wire DATA_Valid;
wire [10:0]CtrlWord;
wire signed[15:0] din;
wire signed[15:0] dout;
TLV1544_CTRL TLV1544_CTRL0(
.Clk(Clk),
.Rst_n(Rst_n),
.Do_Conv(1'b1), //开始转换使能信号
.AD_DONE(AD_DONE), //转换完成信号
.ADC_CHSEL(4'b0), //通道选择
.ADC_DATA(ADC_DATA), //采样结果
.DATA_Valid(DATA_Valid),
.TLV1544_SDO(TLV1544_SDO),
.TLV1544_SDI(TLV1544_SDI),
.TLV1544_SCLK(TLV1544_SCLK),
.TLV1544_NCS(TLV1544_NCS),
.TLV1544_FS(TLV1544_FS),
.TLV1544_EOC(TLV1544_EOC)
);
ADC_to_filter ADC_to_filter0(
.ADC_DATA(ADC_DATA),
.din(din)
);
myiir myiir0(
.rst(Rst_n),
.clk(Clk),
.din(din),
.dout(dout),
.din_valid(DATA_Valid),
.dout_valid()
);
filter_to_DAC filter_to_DAC0(
.dout(dout),
.CtrlWord(CtrlWord)
);
TLC5620_CTRL TLC5620_CTRL0(
.Clk(Clk),
.Rst_n(Rst_n),
.UpdateReq(1'b1),
.CtrlWord(CtrlWord),
.UpdateDone(),
.TLC5620_CLK(TLC5620_CLK),
.TLC5620_DATA(TLC5620_DATA),
.TLC5620_LOAD(TLC5620_LOAD),
.TLC5620_LDAC(TLC5620_LDAC)
);
endmodule

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2.2 TLV1544驱动

TLV1544_CTRL.V

module TLV1544_CTRL(
Clk,
Rst_n,
Do_Conv, //开始转换使能信号
AD_DONE, //转换完成信号
ADC_CHSEL, //通道选择
ADC_DATA, //采样结果
DATA_Valid,
TLV1544_SDO,
TLV1544_SDI,
TLV1544_SCLK,
TLV1544_NCS,
TLV1544_FS,
TLV1544_EOC
);
input Clk;
input Rst_n;
input Do_Conv; //开始转换使能信号
input [3:0]ADC_CHSEL; //通道选择
output reg [9:0]ADC_DATA; //采样结果
output reg AD_DONE; //转换完成信号
output reg DATA_Valid;
input TLV1544_SDO;
input TLV1544_EOC;
output reg TLV1544_SDI;
output reg TLV1544_SCLK;
output reg TLV1544_NCS;
output wire TLV1544_FS;
assign TLV1544_FS = 1'b1;
reg [7:0] LSM_CNT;//序列计数器
reg [9:0] rADC_DATA;
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)
LSM_CNT <= 8'd0;
else if(LSM_CNT <204 && (TLV1544_EOC == 1'b1) && (Do_Conv || LSM_CNT > 8'd0))
LSM_CNT <= LSM_CNT + 1'b1;
else if(LSM_CNT < 204 && (TLV1544_EOC == 1'b0))
LSM_CNT <= LSM_CNT;
else if(LSM_CNT == 204 && (TLV1544_EOC == 1'b1))
LSM_CNT <= 8'd0;
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)begin
rADC_DATA <= 10'd0;
TLV1544_SDI <= 1'b0;
TLV1544_SCLK <= 1'b0;
TLV1544_NCS <= 1'b1;
AD_DONE <= 1'b0;
DATA_Valid <= 1'b0;
ADC_DATA <= 10'd0;
end
else begin
case(LSM_CNT)
0:
begin
rADC_DATA <= 10'd0;
TLV1544_SDI <= 1'b0;
TLV1544_SCLK <= 1'b0;
TLV1544_NCS <= 1'b1;
AD_DONE <= 1'b0;
end
1:
begin
TLV1544_NCS <= 1'b0;
TLV1544_SDI <= ADC_CHSEL[3];
end
9:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[9] <= TLV1544_SDO;
end
19:
begin
TLV1544_SDI <= ADC_CHSEL[2];
TLV1544_SCLK <= 1'b0;
end
29:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[8] <= TLV1544_SDO;
end
39:
begin
TLV1544_SDI <= ADC_CHSEL[1];
TLV1544_SCLK <= 1'b0;
end
49:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[7] <= TLV1544_SDO;
end
59:
begin
TLV1544_SDI <= ADC_CHSEL[0];
TLV1544_SCLK <= 1'b0;
end
69:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[6] <= TLV1544_SDO;
end
79:TLV1544_SCLK <= 1'b0;
89:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[5] <= TLV1544_SDO;
end
99:TLV1544_SCLK <= 1'b0;
109:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[4] <= TLV1544_SDO;
end
119:TLV1544_SCLK <= 1'b0;
129:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[3] <= TLV1544_SDO;
end
139:TLV1544_SCLK <= 1'b0;
149:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[2] <= TLV1544_SDO;
end
159:TLV1544_SCLK <= 1'b0;
169:
begin
TLV1544_SCLK <= 1'b1;
rADC_DATA[1] <= TLV1544_SDO;
end
179:TLV1544_SCLK <= 1'b0;
189:
begin
TLV1544_SCLK <= 1'b1;
//rADC_DATA[0] <= TLV1544_SDO;
if(TLV1544_EOC)
DATA_Valid <= 1'b1;
else
DATA_Valid <= 1'b0;
ADC_DATA <= {rADC_DATA[9:1],TLV1544_SDO};
end
199:
begin
TLV1544_SCLK <= 1'b0;
TLV1544_NCS <= 1'b1;
end
204:AD_DONE <= 1'b1;
default:DATA_Valid <= 1'b0;
endcase
end
endmodule

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2.3 ADC转filter模块

ADC_to_filter.V

module ADC_to_filter (
ADC_DATA,
din
);
input [9:0]ADC_DATA;
output signed[15:0]din;
assign din = ADC_DATA<<6;
endmodule

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2.4 myiir模块
myiir.V

module myiir(
rst,
clk,
din,
dout,
din_valid,
dout_valid,
);
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output reg signed[15:0] dout;
output reg dout_valid;
wire signed[15:0] dout1;
wire signed[15:0] dout2;
wire signed[15:0] dout3;
wire signed[15:0] dout4;
wire signed[15:0] dout5;
wire signed[15:0] dout_reg;
wire din_valid1;
wire dout_valid1;
wire din_valid2;
wire dout_valid2;
wire din_valid3;
wire dout_valid3;
wire din_valid4;
wire dout_valid4;
wire din_valid5;
wire dout_valid5;
wire din_valid6;
wire dout_valid6;
assign din_valid1=din_valid;
assign din_valid2=dout_valid1;
assign din_valid3=dout_valid2;
assign din_valid4=dout_valid3;
assign din_valid5=dout_valid4;
assign din_valid6=dout_valid5;
//assign dout_prevalid=dout_valid1;
myiir_first_step U1(
.rst(rst),
.clk(clk),
.din(din),
.dout(dout1),
.din_valid(din_valid1),
.dout_valid(dout_valid1)
);
myiir_second_step U2(
.rst(rst),
.clk(clk),
.din(dout1),
.dout(dout2),
.din_valid(din_valid2),
.dout_valid(dout_valid2)
);
myiir_third_step U3(
.rst(rst),
.clk(clk),
.din(dout2),
.dout(dout3),
.din_valid(din_valid3),
.dout_valid(dout_valid3)
);
myiir_fourth_step U4(
.rst(rst),
.clk(clk),
.din(dout3),
.dout(dout4),
.din_valid(din_valid4),
.dout_valid(dout_valid4)
);
myiir_fifth_step U5(
.rst(rst),
.clk(clk),
.din(dout4),
.dout(dout5),
.din_valid(din_valid5),
.dout_valid(dout_valid5)
);
myiir_sixth_step U6(
.rst(rst),
.clk(clk),
.din(dout5),
.dout(dout_reg),
.din_valid(din_valid6),
.dout_valid(dout_valid6)
);
always @(negedge rst,posedge clk) begin
if(!rst) begin
dout<=16'd0;
dout_valid=1'b0;
end
else if(dout_valid6) begin
dout_valid=1'b1;
dout<=dout_reg;
end
else begin
dout<=dout;
dout_valid=1'b0;
end
end
endmodule

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2.5 filter转DAC模块

filter_to_DAC.V

module filter_to_DAC
(
dout,
CtrlWord
);
input signed[15:0] dout;
output [10:0]CtrlWord;
assign CtrlWord[7:0]=dout[7:0];
assign CtrlWord[10:8]=3'b0;
endmodule

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2.6 TLC5620驱动
TLC5620_CTRL.V

module TLC5620_CTRL(
Clk,
Rst_n,
UpdateReq,
CtrlWord,
UpdateDone,
TLC5620_CLK,
TLC5620_DATA,
TLC5620_LOAD,
TLC5620_LDAC
);
input Clk;
input Rst_n;
input UpdateReq;
input [10:0]CtrlWord;
output reg UpdateDone;
output reg TLC5620_CLK;
output reg TLC5620_DATA;
output reg TLC5620_LOAD;
output reg TLC5620_LDAC;
reg [9:0] Cnt;
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)
Cnt <= 10'd0;
else if(UpdateReq == 1 | (Cnt != 10'd0))begin
if(Cnt == 10'd820)
Cnt <= 10'd0;
else
Cnt <= Cnt + 10'd1;
end
else
Cnt <= 10'd0;
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)begin
TLC5620_CLK <= 1'b0;
TLC5620_DATA <= 1'b0;
TLC5620_LOAD <= 1'b0;
TLC5620_LDAC <= 1'b0;
UpdateDone <= 1'b0;
end
else begin
case(Cnt)
0:
begin
TLC5620_CLK <= 1'b0;
TLC5620_DATA <= 1'b0;
TLC5620_LOAD <= 1'b1;
TLC5620_LDAC <= 1'b0;
UpdateDone <= 1'b0;
end
10:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[10];
end
40: TLC5620_CLK <= 1'b0;
70:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[9];
end
100: TLC5620_CLK <= 1'b0;
130:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[8];
end
160: TLC5620_CLK <= 1'b0;
190:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[7];
end
220: TLC5620_CLK <= 1'b0;
250:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[6];
end
280: TLC5620_CLK <= 1'b0;
310:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[5];
end
340: TLC5620_CLK <= 1'b0;
370:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[4];
end
400: TLC5620_CLK <= 1'b0;
430:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[3];
end
460: TLC5620_CLK <= 1'b0;
490:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[2];
end
520: TLC5620_CLK <= 1'b0;
550:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[1];
end
580: TLC5620_CLK <= 1'b0;
610:
begin
TLC5620_CLK <= 1'b1;
TLC5620_DATA <= CtrlWord[0];
end
640: TLC5620_CLK <= 1'b0;
670:TLC5620_LOAD <= 1'b0;
800:TLC5620_LOAD <= 1'b1;
820:UpdateDone <= 1'b1;
default:;
endcase
end
endmodule

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2.7 myiir_first_step模块
myiir_first_step.V

module myiir_first_step(
rst,
clk,
din,
dout,
din_valid,
dout_valid
);
parameter b0=16145;
parameter b1=-23383;
parameter b2=16145;
parameter a1=-26283;
parameter a2=14526;
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output signed[15:0] dout;
output dout_valid;
reg[4:0] cState,nState;
reg signed[15:0] x_reg0;
reg signed[15:0] x_reg1;
reg signed[31:0] x_mul1;
reg signed[31:0] x_mul2;
reg signed[31:0] x_mul3;
wire signed[15:0] x_int_mul1;
wire signed[15:0] x_int_mul2;
wire signed[15:0] x_int_mul3;
reg signed[17:0] x_sum;
wire signed[15:0] x_temp;
reg signed[15:0] y_reg0;
reg signed[15:0] y_reg1;
reg signed[31:0] y_mul1;
reg signed[31:0] y_mul2;
wire signed[15:0] y_int_mul1;
wire signed[15:0] y_int_mul2;
reg signed[16:0] y_sum;
wire signed[15:0] y_temp;
reg signed[16:0] dout_sum;
wire signed[15:0] dout_temp;
always @(negedge rst,posedge clk) begin
if(!rst) begin
cState<=0;
end
else begin
cState<=nState;
end
end
always @(*) begin
case(cState)
0:if(din_valid) begin
nState<=1;
end
else begin
nState<=0;
end
1:nState<=2;
2:nState<=3;
3:nState<=4;
4:nState<=5;
5:nState<=6;
6:nState<=0;
default:nState<=nState;
endcase
end
always @(*) begin
if(rst) begin
case(cState)
1:x_mul1=b0*din;
2:begin
x_mul2=b1*x_reg0;
y_mul1=a1*y_reg0;
end
3:begin
x_mul3=b2*x_reg1;
y_mul2=a2*y_reg1;
end
4:begin
x_sum=x_int_mul1+x_int_mul2+x_int_mul3;
y_sum=y_int_mul1+y_int_mul2;
end
5:dout_sum=x_temp-y_temp;
default:;
endcase
end
end
always @(cState) begin
if(rst) begin
if(cState==4) begin
x_reg0<=din;
x_reg1<=x_reg0;
end
else begin
x_reg0<=x_reg0;
x_reg1<=x_reg1;
end
end
else begin
x_reg0<=16'd0;
x_reg1<=16'd0;
end
end
always @(cState) begin
if(rst) begin
if(cState==6) begin
y_reg0<=dout;
y_reg1<=y_reg0;
end
else begin
y_reg0<=y_reg0;
y_reg1<=y_reg1;
end
end
else begin
y_reg0<=16'd0;
y_reg1<=16'd0;
end
end
assign x_int_mul1=(x_mul1[31]^x_mul1[30])?x_mul1[31:16]:x_mul1[30:15];
assign x_int_mul2=(x_mul2[31]^x_mul2[30])?x_mul2[31:16]:x_mul2[30:15];
assign x_int_mul3=(x_mul3[31]^x_mul3[30])?x_mul3[31:16]:x_mul3[30:15];
assign x_temp=(x_sum[17:15]==3'b000||x_sum[17:15]==3'b111)?x_sum[15:0]:(x_sum[17])?16'h8000:16'h7fff;
assign y_int_mul1=(y_mul1[31]^y_mul1[30])?y_mul1[31:16]:y_mul1[30:15];
assign y_int_mul2=(y_mul2[31]^y_mul2[30])?y_mul2[31:16]:y_mul2[30:15];
assign y_temp=(y_sum[16:15]==2'b00||y_sum[16:15]==2'b11)?y_sum[15:0]:(y_sum[16])?16'h8000:16'h7fff;
assign dout_temp=(dout_sum[16:15]==2'b00||dout_sum[16:15]==2'b11)?dout_sum[15:0]:(dout_sum[16])?16'h8000:16'h7fff;
assign dout=(!rst)?16'd0:dout_temp;
assign dout_valid=(cState==6 && nState==0)?1'b1:1'b0;
endmodule

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2.8 myiir_second_step模块
myiir_second_step.V

module myiir_second_step(
rst,
clk,
din,
dout,
din_valid,
dout_valid
);
parameter b0=13569;
parameter b1=-18494;
parameter b2=13569;
parameter a1=-19700;
parameter a2=9712;
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output signed[15:0] dout;
output dout_valid;
reg[4:0] cState,nState;
reg signed[15:0] x_reg0;
reg signed[15:0] x_reg1;
reg signed[31:0] x_mul1;
reg signed[31:0] x_mul2;
reg signed[31:0] x_mul3;
wire signed[15:0] x_int_mul1;
wire signed[15:0] x_int_mul2;
wire signed[15:0] x_int_mul3;
reg signed[17:0] x_sum;
wire signed[15:0] x_temp;
reg signed[15:0] y_reg0;
reg signed[15:0] y_reg1;
reg signed[31:0] y_mul1;
reg signed[31:0] y_mul2;
wire signed[15:0] y_int_mul1;
wire signed[15:0] y_int_mul2;
reg signed[16:0] y_sum;
wire signed[15:0] y_temp;
reg signed[16:0] dout_sum;
wire signed[15:0] dout_temp;
always @(negedge rst,posedge clk) begin
if(!rst) begin
cState<=0;
end
else begin
cState<=nState;
end
end
always @(*) begin
case(cState)
0:if(din_valid) begin
nState<=1;
end
else begin
nState<=0;
end
1:nState<=2;
2:nState<=3;
3:nState<=4;
4:nState<=5;
5:nState<=6;
6:nState<=0;
default:nState<=nState;
endcase
end
always @(*) begin
if(rst) begin
case(cState)
1:x_mul1=b0*din;
2:begin
x_mul2=b1*x_reg0;
y_mul1=a1*y_reg0;
end
3:begin
x_mul3=b2*x_reg1;
y_mul2=a2*y_reg1;
end
4:begin
x_sum=x_int_mul1+x_int_mul2+x_int_mul3;
y_sum=y_int_mul1+y_int_mul2;
end
5: dout_sum=x_temp-y_temp;
default:;
endcase
end
end
assign x_int_mul1=(x_mul1[31]^x_mul1[30])?x_mul1[31:16]:x_mul1[30:15];
assign x_int_mul2=(x_mul2[31]^x_mul2[30])?x_mul2[31:16]:x_mul2[30:15];
assign x_int_mul3=(x_mul3[31]^x_mul3[30])?x_mul3[31:16]:x_mul3[30:15];
assign x_temp=(x_sum[17:15]==3'b000||x_sum[17:15]==3'b111)?x_sum[15:0]:(x_sum[17])?16'h8000:16'h7fff;
assign y_int_mul1=(y_mul1[31]^y_mul1[30])?y_mul1[31:16]:y_mul1[30:15];
assign y_int_mul2=(y_mul2[31]^y_mul2[30])?y_mul2[31:16]:y_mul2[30:15];
assign y_temp=(y_sum[16:15]==2'b00||y_sum[16:15]==2'b11)?y_sum[15:0]:(y_sum[16])?16'h8000:16'h7fff;
assign dout_temp=(dout_sum[16:15]==2'b00||dout_sum[16:15]==2'b11)?dout_sum[15:0]:(dout_sum[16])?16'h8000:16'h7fff;
assign dout=(!rst)?16'd0:dout_temp;
always @(cState) begin
if(rst) begin
if(cState==4) begin
x_reg0<=din;
x_reg1<=x_reg0;
end
else begin
x_reg0<=x_reg0;
x_reg1<=x_reg1;
end
end
else begin
x_reg0<=16'd0;
x_reg1<=16'd0;
end
end
always @(cState) begin
if(rst) begin
if(cState==6) begin
y_reg0<=dout;
y_reg1<=y_reg0;
end
else begin
y_reg0<=y_reg0;
y_reg1<=y_reg1;
end
end
else begin
y_reg0<=16'd0;
y_reg1<=16'd0;
end
end
assign dout_valid=(cState==6 && nState==0)?1'b1:1'b0;
endmodule

复制代码

2.9 myiir_third_step模块
myiir_third_step.V

module myiir_third_step(
rst,
clk,
din,
dout,
din_valid,
dout_valid
);
parameter b0=10302;
parameter b1=-11731;
parameter b2=10302;
parameter a1=-11633;
parameter a2=5561;
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output signed[15:0] dout;
output dout_valid;
reg[4:0] cState,nState;
reg signed[15:0] x_reg0;
reg signed[15:0] x_reg1;
reg signed[31:0] x_mul1;
reg signed[31:0] x_mul2;
reg signed[31:0] x_mul3;
wire signed[15:0] x_int_mul1;
wire signed[15:0] x_int_mul2;
wire signed[15:0] x_int_mul3;
reg signed[17:0] x_sum;
wire signed[15:0] x_temp;
reg signed[15:0] y_reg0;
reg signed[15:0] y_reg1;
reg signed[31:0] y_mul1;
reg signed[31:0] y_mul2;
wire signed[15:0] y_int_mul1;
wire signed[15:0] y_int_mul2;
reg signed[16:0] y_sum;
wire signed[15:0] y_temp;
reg signed[16:0] dout_sum;
wire signed[15:0] dout_temp;
always @(negedge rst,posedge clk) begin
if(!rst) begin
cState<=0;
end
else begin
cState<=nState;
end
end
always @(*) begin
case(cState)
0:if(din_valid) begin
nState<=1;
end
else begin
nState<=0;
end
1:nState<=2;
2:nState<=3;
3:nState<=4;
4:nState<=5;
5:nState<=6;
6:nState<=0;
default:nState<=nState;
endcase
end
always @(*) begin
if(rst) begin
case(cState)
1:x_mul1=b0*din;
2:begin
x_mul2=b1*x_reg0;
y_mul1=a1*y_reg0;
end
3:begin
x_mul3=b2*x_reg1;
y_mul2=a2*y_reg1;
end
4:begin
x_sum=x_int_mul1+x_int_mul2+x_int_mul3;
y_sum=y_int_mul1+y_int_mul2;
end
5: dout_sum=x_temp-y_temp;
default:;
endcase
end
end
assign x_int_mul1=(x_mul1[31]^x_mul1[30])?x_mul1[31:16]:x_mul1[30:15];
assign x_int_mul2=(x_mul2[31]^x_mul2[30])?x_mul2[31:16]:x_mul2[30:15];
assign x_int_mul3=(x_mul3[31]^x_mul3[30])?x_mul3[31:16]:x_mul3[30:15];
assign x_temp=(x_sum[17:15]==3'b000||x_sum[17:15]==3'b111)?x_sum[15:0]:(x_sum[17])?16'h8000:16'h7fff;
assign y_int_mul1=(y_mul1[31]^y_mul1[30])?y_mul1[31:16]:y_mul1[30:15];
assign y_int_mul2=(y_mul2[31]^y_mul2[30])?y_mul2[31:16]:y_mul2[30:15];
assign y_temp=(y_sum[16:15]==2'b00||y_sum[16:15]==2'b11)?y_sum[15:0]:(y_sum[16])?16'h8000:16'h7fff;
assign dout_temp=(dout_sum[16:15]==2'b00||dout_sum[16:15]==2'b11)?dout_sum[15:0]:(dout_sum[16])?16'h8000:16'h7fff;
assign dout=(!rst)?16'd0:dout_temp;
always @(cState) begin
if(rst) begin
if(cState==4) begin
x_reg0<=din;
x_reg1<=x_reg0;
end
else begin
x_reg0<=x_reg0;
x_reg1<=x_reg1;
end
end
else begin
x_reg0<=16'd0;
x_reg1<=16'd0;
end
end
always @(cState) begin
if(rst) begin
if(cState==6) begin
y_reg0<=dout;
y_reg1<=y_reg0;
end
else begin
y_reg0<=y_reg0;
y_reg1<=y_reg1;
end
end
else begin
y_reg0<=16'd0;
y_reg1<=16'd0;
end
end
assign dout_valid=(cState==6 && nState==0)?1'b1:1'b0;
endmodule

复制代码

2.10 myiir_fourth_step模块
myiir_fourth_step.V

module myiir_fourth_step(
rst,
clk,
din,
dout,
din_valid,
dout_valid
);
parameter b0=6724;
parameter b1=-4060;
parameter b2=6724;
parameter a1=-7317;
parameter a2=2520;
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output signed[15:0] dout;
output dout_valid;
reg[4:0] cState,nState;
reg signed[15:0] x_reg0;
reg signed[15:0] x_reg1;
reg signed[31:0] x_mul1;
reg signed[31:0] x_mul2;
reg signed[31:0] x_mul3;
wire signed[15:0] x_int_mul1;
wire signed[15:0] x_int_mul2;
wire signed[15:0] x_int_mul3;
reg signed[17:0] x_sum;
wire signed[15:0] x_temp;
reg signed[15:0] y_reg0;
reg signed[15:0] y_reg1;
reg signed[31:0] y_mul1;
reg signed[31:0] y_mul2;
wire signed[15:0] y_int_mul1;
wire signed[15:0] y_int_mul2;
reg signed[16:0] y_sum;
wire signed[15:0] y_temp;
reg signed[16:0] dout_sum;
wire signed[15:0] dout_temp;
always @(negedge rst,posedge clk) begin
if(!rst) begin
cState<=0;
end
else begin
cState<=nState;
end
end
always @(*) begin
case(cState)
0:if(din_valid) begin
nState<=1;
end
else begin
nState<=0;
end
1:nState<=2;
2:nState<=3;
3:nState<=4;
4:nState<=5;
5:nState<=6;
6:nState<=0;
default:nState<=nState;
endcase
end
always @(*) begin
if(rst) begin
case(cState)
1:x_mul1=b0*din;
2:begin
x_mul2=b1*x_reg0;
y_mul1=a1*y_reg0;
end
3:begin
x_mul3=b2*x_reg1;
y_mul2=a2*y_reg1;
end
4:begin
x_sum=x_int_mul1+x_int_mul2+x_int_mul3;
y_sum=y_int_mul1+y_int_mul2;
end
5: dout_sum=x_temp-y_temp;
default:;
endcase
end
end
assign x_int_mul1=(x_mul1[31]^x_mul1[30])?x_mul1[31:16]:x_mul1[30:15];
assign x_int_mul2=(x_mul2[31]^x_mul2[30])?x_mul2[31:16]:x_mul2[30:15];
assign x_int_mul3=(x_mul3[31]^x_mul3[30])?x_mul3[31:16]:x_mul3[30:15];
assign x_temp=(x_sum[17:15]==3'b000||x_sum[17:15]==3'b111)?x_sum[15:0]:(x_sum[17])?16'h8000:16'h7fff;
assign y_int_mul1=(y_mul1[31]^y_mul1[30])?y_mul1[31:16]:y_mul1[30:15];
assign y_int_mul2=(y_mul2[31]^y_mul2[30])?y_mul2[31:16]:y_mul2[30:15];
assign y_temp=(y_sum[16:15]==2'b00||y_sum[16:15]==2'b11)?y_sum[15:0]:(y_sum[16])?16'h8000:16'h7fff;
assign dout_temp=(dout_sum[16:15]==2'b00||dout_sum[16:15]==2'b11)?dout_sum[15:0]:(dout_sum[16])?16'h8000:16'h7fff;
assign dout=(!rst)?16'd0:dout_temp;
always @(cState) begin
if(rst) begin
case(cState)
4: begin
x_reg0<=din;
x_reg1<=x_reg0;
end
default:begin
x_reg0<=x_reg0;
x_reg1<=x_reg1;
end
endcase
end
else begin
x_reg0<=16'd0;
x_reg1<=16'd0;
end
end
always @(cState) begin
if(rst) begin
if(cState==6) begin
y_reg0<=dout;
y_reg1<=y_reg0;
end
else begin
y_reg0<=y_reg0;
y_reg1<=y_reg1;
end
end
else begin
y_reg0<=16'd0;
y_reg1<=16'd0;
end
end
assign dout_valid=(cState==6 && nState==0)?1'b1:1'b0;
endmodule

复制代码

2.11 myiir_fifth_step模块
myiir_fifth_step.V

module myiir_fifth_step(
rst,
clk,
din,
dout,
din_valid,
dout_valid
);
parameter b0=3736;
parameter b1=-2448;
parameter b2=3736;
parameter a1=-3526;
parameter a2=921;
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output signed[15:0] dout;
output dout_valid;
reg[4:0] cState,nState;
reg signed[15:0] x_reg0;
reg signed[15:0] x_reg1;
reg signed[31:0] x_mul1;
reg signed[31:0] x_mul2;
reg signed[31:0] x_mul3;
wire signed[15:0] x_int_mul1;
wire signed[15:0] x_int_mul2;
wire signed[15:0] x_int_mul3;
reg signed[17:0] x_sum;
wire signed[15:0] x_temp;
reg signed[15:0] y_reg0;
reg signed[15:0] y_reg1;
reg signed[31:0] y_mul1;
reg signed[31:0] y_mul2;
wire signed[15:0] y_int_mul1;
wire signed[15:0] y_int_mul2;
reg signed[16:0] y_sum;
wire signed[15:0] y_temp;
reg signed[16:0] dout_sum;
wire signed[15:0] dout_temp;
always @(negedge rst,posedge clk) begin
if(!rst) begin
cState<=0;
end
else begin
cState<=nState;
end
end
always @(*) begin
case(cState)
0:if(din_valid) begin
nState<=1;
end
else begin
nState<=0;
end
1:nState<=2;
2:nState<=3;
3:nState<=4;
4:nState<=5;
5:nState<=6;
6:nState<=0;
default:nState<=nState;
endcase
end
always @(*) begin
if(rst) begin
case(cState)
1:x_mul1=b0*din;
2:begin
x_mul2=b1*x_reg0;
y_mul1=a1*y_reg0;
end
3:begin
x_mul3=b2*x_reg1;
y_mul2=a2*y_reg1;
end
4:begin
x_sum=x_int_mul1+x_int_mul2+x_int_mul3;
y_sum=y_int_mul1+y_int_mul2;
end
5: dout_sum=x_temp-y_temp;
default:;
endcase
end
end
assign x_int_mul1=(x_mul1[31]^x_mul1[30])?x_mul1[31:16]:x_mul1[30:15];
assign x_int_mul2=(x_mul2[31]^x_mul2[30])?x_mul2[31:16]:x_mul2[30:15];
assign x_int_mul3=(x_mul3[31]^x_mul3[30])?x_mul3[31:16]:x_mul3[30:15];
assign x_temp=(x_sum[17:15]==3'b000||x_sum[17:15]==3'b111)?x_sum[15:0]:(x_sum[17])?16'h8000:16'h7fff;
assign y_int_mul1=(y_mul1[31]^y_mul1[30])?y_mul1[31:16]:y_mul1[30:15];
assign y_int_mul2=(y_mul2[31]^y_mul2[30])?y_mul2[31:16]:y_mul2[30:15];
assign y_temp=(y_sum[16:15]==2'b00||y_sum[16:15]==2'b11)?y_sum[15:0]:(y_sum[16])?16'h8000:16'h7fff;
assign dout_temp=(dout_sum[16:15]==2'b00||dout_sum[16:15]==2'b11)?dout_sum[15:0]:(dout_sum[16])?16'h8000:16'h7fff;
assign dout=(!rst)?16'd0:dout_temp;
always @(cState) begin
if(rst) begin
case(cState)
4: begin
x_reg0<=din;
x_reg1<=x_reg0;
end
default:begin
x_reg0<=x_reg0;
x_reg1<=x_reg1;
end
endcase
end
else begin
x_reg0<=16'd0;
x_reg1<=16'd0;
end
end
always @(cState) begin
if(rst) begin
if(cState==6) begin
y_reg0<=dout;
y_reg1<=y_reg0;
end
else begin
y_reg0<=y_reg0;
y_reg1<=y_reg1;
end
end
else begin
y_reg0<=16'd0;
y_reg1<=16'd0;
end
end
assign dout_valid=(cState==6 && nState==0)?1'b1:1'b0;
endmodule

复制代码

2.12 myiir_sixth_step模块
myiir_sixth_step.V

module myiir_sixth_step(
rst,
clk,
din,
dout,
din_valid,
dout_valid
);
parameter b0=9119;
parameter b1=9119;
parameter a1=-4044;
input rst;
input clk;
input signed[15:0] din;
input din_valid;
output signed[15:0] dout;
output dout_valid;
reg[4:0] cState,nState;
reg signed[15:0] x_reg0;
reg signed[31:0] x_mul1;
reg signed[31:0] x_mul2;
wire signed[15:0] x_int_mul1;
wire signed[15:0] x_int_mul2;
reg signed[16:0] x_sum;
wire signed[15:0] x_temp;
reg signed[15:0] y_reg0;
reg signed[31:0] y_mul1;
wire signed[15:0] y_int_mul1;
reg signed[16:0] dout_sum;
wire signed[15:0] dout_temp;
always @(negedge rst,posedge clk) begin
if(!rst) begin
cState<=0;
end
else begin
cState<=nState;
end
end
always @(*) begin
case(cState)
0:if(din_valid) begin
nState<=1;
end
else begin
nState<=0;
end
1:nState<=2;
2:nState<=3;
3:nState<=4;
4:nState<=5;
5:nState<=0;
default:nState<=0;
endcase
end
always @(*) begin
if(rst) begin
case(cState)
1:x_mul1=b0*din;
2:begin
x_mul2=b1*x_reg0;
y_mul1=a1*y_reg0;
end
3:begin
x_sum=x_int_mul1+x_int_mul2;
end
4:begin
dout_sum=x_temp-y_int_mul1;
end
default:;
endcase
end
end
assign x_int_mul1=(x_mul1[31]^x_mul1[30])?x_mul1[31:16]:x_mul1[30:15];
assign x_int_mul2=(x_mul2[31]^x_mul2[30])?x_mul2[31:16]:x_mul2[30:15];
assign x_temp=(x_sum[16:15]==2'b00||x_sum[16:15]==2'b11)?x_sum[15:0]:(x_sum[16])?16'h8000:16'h7fff;
assign y_int_mul1=(y_mul1[31]^y_mul1[30])?y_mul1[31:16]:y_mul1[30:15];
assign dout_temp=(dout_sum[16:15]==2'b00||dout_sum[16:15]==2'b11)?dout_sum[15:0]:(dout_sum[16])?16'h8000:16'h7fff;
assign dout=(!rst)?16'd0:dout_temp;
always @(cState) begin
if(rst) begin
if(cState==4) begin
x_reg0<=din;
end
else begin
x_reg0<=x_reg0;
end
end
else begin
x_reg0<=16'd0;
end
end
always @(cState) begin
if(rst) begin
if(cState==5) begin
y_reg0<=dout;
end
else begin
y_reg0<=y_reg0;
end
end
else begin
y_reg0<=16'd0;
end
end
assign dout_valid=(cState==5 && nState==0)?1'b1:1'b0;
endmodule

复制代码

代码到这里终于结束了！辛苦观看。。
3.仿真与引脚分配
3.1 仿真
实验使用modelsim进行仿真，从matlab获得量化后的输入波形文件，经过仿真后得到滤波后的波形。

3.2 引脚分配

4.心得

本次实验好艰辛啊！从最开始的晕头晕脑，到最后有效果，时间挺长的，但确实学到了许多！通过这次实验，不仅更加熟练地学习到了FPGA设计的流程，更加深了数字信号处理滤波器的设计和实现！重要是坚持!!!

5.视频地址

前篇
http://v.youku.com/v_show/id_XMjcyMjkwNDY3Mg==.html
后篇
http://v.youku.com/v_show/id_XMjcyMjkyOTYzMg==.html

【转】基于FPGA的IIR滤波器

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