用verilog语言写一段低通滤波代码

我可以回答这个问题。以下是一段用 Verilog 语言编写的低通滤波器代码：

module lowpass_filter(input clk, input reset, input signed [15:0] data_in, output signed [15:0] data_out);

parameter CUTOFF_FREQ = 1000; // 截止频率为 1000 Hz
parameter SAMPLE_RATE = 48000; // 采样率为 48000 Hz

reg signed [15:0] x1, x2, y1, y2;
reg signed [15:0] coef1, coef2, coef3;

assign coef1 = (2 * 3.1415926 * CUTOFF_FREQ) / SAMPLE_RATE;
assign coef2 = 2 * exp(-coef1);
assign coef3 = 1 - coef2;

always @(posedge clk or posedge reset) begin
if (reset) begin
x1 <= 0;
x2 <= 0;
y1 <= 0;
y2 <= 0;
end else begin
x2 <= x1;
x1 <= data_in;
y2 <= y1;
y1 <= coef3 * (data_in + x2 - coef2 * y2);
data_out <= y1;
end
end

endmodule

这个低通滤波器使用二阶 IIR 滤波器结构，采用差分方程实现。截止频率和采样率可以通过参数进行设置。输入数据为 16 位带符号整数，输出数据也是 16 位带符号整数。