关于quartus的FFT IP核的一些整理

软件版本使用quartus 11.0 sp1    当然11.0也能打开并仿真。

整理的原理图如图所示，原理图不能用于modelsim仿真，所以还需要将原理图转化为Verilog语言文件，file - creat/update—>creat HDL file form current file.便可生成原理图对应的.v文件，并将其作为顶层文件。

其中fft核的生成过程不再赘述，主要是fft_ctrl.v模块的设计，其实也很简单，有一点需要注意，需要根据fft核的输出信号sink_ready信号判断是否开始控制转换。

module fft_ctrl(
				input reset_n,
				input clk,
				input sink_ready,
				output reg  sink_sop,
				output reg sink_eop,
				output reg sink_valid,
				output [7:0] data
				);
			
		//reg[7:0] frame;
		reg[7:0] count,next_count;
		reg [2:0] current_state,next_state;
//		reg sink_sop,sink_eop,sink_valid;
		wire sink_sop_d,sink_eop_d,sink_valid_d;
		
		parameter 	idle		=4'b000,
					go			=4'b001,
					assert_eop	=4'b010,
					wait_state	=4'b100;
					
always@(current_state,sink_ready,count)
	begin
		case(current_state)
			idle:
				begin
					next_count<=0;
					if(sink_ready==1)
						next_state<=go;
					else
						next_state<=idle;
				end
			go:	begin
					if(count<62)
						begin
							next_state<=go;
							next_count<=count+1;
						end
					else
						begin
							next_state<=assert_eop;
							next_count<=count+1;
						end
				end
			assert_eop:
				begin
					next_count<=0;
					next_state<=wait_state;
				end
			wait_state:
				begin
					if(sink_ready==1)
						begin
							next_count<=0;
							next_state<=go;
						end
					else
						begin
							next_count<=count;
							next_state<=wait_state;
						end
				end
		endcase
	end 
	
	
assign data = count+7'd100;
assign sink_sop_d	= ((next_state==go) && (next_count==0))?1:0;
assign sink_eop_d	= (next_state==assert_eop)?1:0;
assign sink_valid_d	= ((next_state==go) || (next_state==assert_eop))?1:0;

always@(negedge reset_n or posedge clk)
	begin
		if(reset_n==0)
			begin
				current_state<=idle;
				count<=0;
				sink_sop<=0;
				sink_eop<=0;
				sink_valid<=0;
			end
		else
			begin
				current_state<=next_state;
				count<=next_count;
				sink_sop<=sink_sop_d;
				sink_eop<=sink_eop_d;
				sink_valid<=sink_valid_d;
			end
	end 
	
endmodule

最后是testbench的编写：

`timescale 1 ps/ 1 ps
module ifft_vlg_tst();

reg clk;
reg rst_n;
reg [1:0] sink_error;
reg source_ready;
// wires                                               
wire [7:0]  rom_data;
wire sink_eop;
wire sink_ready;
wire sink_sop;
wire sink_valid;
wire source_eop;
wire [1:0]  source_error;
wire [5:0]  source_exp;
wire [7:0]  source_imag;
wire [7:0]  source_real;
wire source_sop;
wire source_valid;

// assign statements (if any)                          
ifft i1 (
// port map - connection between master ports and signals/registers   
	.clk(clk),
	.rom_data(rom_data),
	.rst_n(rst_n),
	.sink_eop(sink_eop),
	.sink_error(sink_error),
	.sink_ready(sink_ready),
	.sink_sop(sink_sop),
	.sink_valid(sink_valid),
	.source_eop(source_eop),
	.source_error(source_error),
	.source_exp(source_exp),
	.source_imag(source_imag),
	.source_ready(source_ready),
	.source_real(source_real),
	.source_sop(source_sop),
	.source_valid(source_valid)
);
initial
begin 
   #1 $stop;
	sink_error = 2'b00;
	source_ready = 1'b1;
	rst_n = 0;
	#200 rst_n = 1;   //the time of asset the rst_n must be long time

end 

initial                                                
	begin 
 
														
	clk = 0;
	forever #5 clk = ~clk;

end 

endmodule

其中testbech的有一个地方需要特别注意，

#200 rst_n = 1;

一定要延时足够长的时间，才可以！不然会出现转换数据不连续的结果，原因大概是因为fft核需要一段时间初始化的原因吧

</pre><pre name="code" class="plain">modelsim仿真结果如图：