用verilog写出一个可以生成 4 种基础波形(方波、正弦波、锯齿波、三角波),可以按键控制调频和使用按键控制波形切换的代码和测试代码
时间: 2024-05-04 14:19:57 浏览: 23
以下是基于FPGA实现的Verilog代码,可以生成4种基础波形并支持按键控制调频和波形切换。本代码使用FPGA板载按键,因此需要根据具体的FPGA型号和板载按键的位置进行适当修改。
```verilog
module wave_generator(
input CLK50MHZ,
input [3:0] KEY,
output reg [7:0] DAC
);
reg [31:0] acc = 0; // 32-bit accumulator for frequency control
reg [7:0] phase = 0; // 8-bit phase accumulator for waveform generation
reg [1:0] wave = 0; // 2-bit signal for waveform selection
// waveform generation
always @(posedge CLK50MHZ) begin
case (wave)
2'b00: DAC <= (phase[7]) ? 8'hFF : 8'h00; // square wave
2'b01: DAC <= $signed($bitstoreal(phase[7:0])) + 128; // sine wave
2'b10: DAC <= phase[6:0]; // sawtooth wave
2'b11: DAC <= (phase[7]) ? -(phase[6:0]) : phase[6:0]; // triangle wave
endcase
phase <= phase + 1;
end
// frequency control
always @(posedge CLK50MHZ) begin
if (KEY[0]) acc <= acc + 100000; // increase frequency by 100 kHz
if (KEY[1]) acc <= acc - 100000; // decrease frequency by 100 kHz
if (acc >= 50000000) acc <= acc - 50000000; // limit frequency to 1 Hz - 50 MHz
if (acc <= 0) acc <= acc + 50000000;
phase <= phase + acc[31:24]; // update phase increment based on frequency
end
// waveform selection
always @(posedge CLK50MHZ) begin
case (KEY[2:3])
2'b00: wave <= 2'b00; // square wave
2'b01: wave <= 2'b01; // sine wave
2'b10: wave <= 2'b10; // sawtooth wave
2'b11: wave <= 2'b11; // triangle wave
endcase
end
endmodule
```
以下是测试代码,将使用FPGA板载的8位DAC输出波形,并通过FPGA板载LED显示当前选择的波形。
```verilog
module wave_generator_test(
input CLK50MHZ,
input [3:0] KEY,
output [7:0] DAC,
output [3:0] LED
);
wire [1:0] wave;
wire [7:0] DAC_internal;
wave_generator wg(CLK50MHZ, KEY, DAC_internal);
assign DAC = DAC_internal;
assign LED = wave;
always @(posedge CLK50MHZ) begin
case (KEY[2:3])
2'b00: wave <= 2'b00; // square wave
2'b01: wave <= 2'b01; // sine wave
2'b10: wave <= 2'b10; // sawtooth wave
2'b11: wave <= 2'b11; // triangle wave
endcase
end
endmodule
```