從Matlab到FPGA(Matlab生成coe檔案或mem檔案)

當定點模擬完成後，就需要使用FPGA實現。

這時候需要把之前仿好的濾波器引數或者輸入訊號輸出為coes檔案:

%% output coe file
Ff = fimath('CastBeforeSum', 0, 'OverflowMode', 'Saturate', ...
            'RoundMode', 'round', 'ProductMode', 'SpecifyPrecision', 'SumMode', 'SpecifyPrecision', ...
            'ProductWordLength', 16, 'ProductFractionLength', 15, 'SumWordLength', 16, 'SumFractionLength', 15);
Tf = numerictype('WordLength', 16, 'FractionLength', 15);
wr = 'ram';  % select the output type
outset = fi(hmc.Numerator, Tf, Ff);  % the filter need to be outputted, datatype:fi
outset_len = length(outset);
fp = fopen('D:\tmp\fpga_matlab\FIR.coe','w');
if( strcmp(wr, 'ram') )
fprintf( fp, 'MEMORY_INITIALIZATION_RADIX=16;\n' );
fprintf( fp, 'MEMORY_INITIALIZATION_VECTOR=\n' );
elseif( strcmp(wr, 'fir') )
fprintf( fp, 'radix=10;\n' );
fprintf( fp, 'coefdata=\n' );
end
for i = 1:outset_len
    out = outset(i);
    if( strcmp(wr, 'ram') )
        out_r = real(out); %ram
        out_i = imag(out);
        fprintf(fp, '%s%s\n', out_i.hex, out_r.hex);
    elseif( strcmp(wr, 'fir') )
        out = outset(i);  %fir
        fprintf(fp, '%.17f\n', out);
    end
end
fclose(fp);

由於濾波器在模擬中一個結構體，所以把裡面的引數變成fi物件，這樣可以很方便輸出十六進位制或者二進位制之類。

這裡程式碼還提供了RAM的coe檔案輸出的選擇。

這樣，使用IP核的時候就可以把這些檔案拖進去。

也可以使用原語的方式實現RAM，這樣可以很方便地移植程式碼，如下：

xpm_memory_sdpram # (

  // Common module parameters
  .MEMORY_SIZE        (4096),            //positive integer
  .MEMORY_PRIMITIVE   ("auto"),          //string; "auto", "distributed", "block" or "ultra";
  .CLOCKING_MODE      ("common_clock"),  //string; "common_clock", "independent_clock" 
  .MEMORY_INIT_FILE   (file),          //string; "none" or "<filename>.mem" 
  .MEMORY_INIT_PARAM  (""    ),          //string;
  .USE_MEM_INIT       (1),               //integer; 0,1
  .WAKEUP_TIME        ("disable_sleep"), //string; "disable_sleep" or "use_sleep_pin" 
  .MESSAGE_CONTROL    (0),               //integer; 0,1
  .ECC_MODE           ("no_ecc"),        //string; "no_ecc", "encode_only", "decode_only" or "both_encode_and_decode" 
  .AUTO_SLEEP_TIME    (0),               //Do not Change

  // Port A module parameters
  .WRITE_DATA_WIDTH_A (16),              //positive integer
  .BYTE_WRITE_WIDTH_A (16),              //integer; 8, 9, or WRITE_DATA_WIDTH_A value
  .ADDR_WIDTH_A       (8),               //positive integer

  // Port B module parameters
  .READ_DATA_WIDTH_B  (16),              //positive integer
  .ADDR_WIDTH_B       (8),               //positive integer
  .READ_RESET_VALUE_B ("0"),             //string
  .READ_LATENCY_B     (2),               //non-negative integer
  .WRITE_MODE_B       ("no_change")     //string; "write_first", "read_first", "no_change" 

) xpm_memory_sdpram_inst (

  // Common module ports
  .sleep          (1'b0),

  // Port A module ports
  .clka           (clk),
  .ena            (1'b1),
  .wea            (enw),
  .addra          (waddr),
  .dina           (wdata),
  .injectsbiterra (1'b0),
  .injectdbiterra (1'b0),

  // Port B module ports
  .clkb           (clk),
  .rstb           (1'b0),
  .enb            (1'b1),
  .regceb         (1'b1),
  .addrb          (raddr),
  .doutb          (rdata),
  .sbiterrb       (),
  .dbiterrb       ()
);

這樣就例化了一個讀寫RAM

這裡RAM的初始化資料是mem檔案，可以用如下Matlab程式碼輸出：

outset = [0;ER1];
outset = fi(outset, T, F);  % the filter need to be outputted, datatype:fi
outset_len = length(outset);
fp = fopen('D:\tmp\fpga_matlab\ER1.mem','w');
for i = 1:outset_len
    out = outset(i);
    fprintf(fp, '@%04x %04x\n', (i-1), out.int);
end
fclose(fp);

使用Verilog測試時，需要讀取txt檔案的資料輸入模擬的模組，並把輸出的資料儲存到txt再用Matlab讀取出來分析，Matlab側輸出資料到txt的程式碼如下：

%% output fi object
outset = RR;%fi(Tx, T, F);  % the filter need to be outputted, datatype:fi
outset_len = length(outset);
% if(outset_len>10000)
%     outset_len = 10000;
% end
fp = fopen('D:\tmp\fpga_matlab\Tx.txt','w');
for i = 1:outset_len
    out = outset(i);
    r_out = real(out);
    i_out = imag(out);
    fprintf(fp, '%s %s\n', r_out.dec, i_out.dec);
end
fclose(fp);

Matlab側讀取txt的程式碼為：

%% input fi object
fp = fopen('D:\tmp\fpga_matlab\Rx.txt','r');
in = textscan(fp, '%s');
fclose(fp);
ins = in{1,1};
in_l = length(ins);
rx = zeros( in_l/2, 1 );
for i = 1:2:in_l
    in_r = str2double(ins{i});
    in_i = str2double(ins{i+1});
    rx( (i+1)/2 ) = in_r/(2^14) + 1j*in_i/(2^14);
end

對應的verilog程式碼如下：

integer fp_r, fp_w, cnt, r_n, w_n;
// read data
initial begin
	fp_r = $fopen("D:/tmp/fpga_matlab/Tx1.txt", "r");
	r_n = 0;
	s_axis_data_tvalid = 0;
	s_axis_data_tdata = 0;
	wait(rst_n==1);
	@(posedge clk)
	while(!$feof(fp_r)) begin
	#1
	cnt = $fscanf(fp_r, "%d %d", data_in_I, data_in_Q);
	r_n = r_n + 1;
	s_axis_data_tdata = { data_in_Q[15:0], data_in_I[15:0] };
	s_axis_data_tvalid = 1;
	@(posedge clk);
	#1
	s_axis_data_tvalid = 0;
	#(1*PERIOD);
	end
	s_axis_data_tvalid = 0;
	s_axis_data_tdata = 0;
	$fclose(fp_r);
end

// write data
initial begin
	fp_w = $fopen("D:/tmp/fpga_matlab/Tx2_fpga.txt","w");//以寫的方式開啟檔案
	w_n = 0;
	@(posedge m_axis_data_tvalid)
	while(m_axis_data_tvalid)
	begin
		@(posedge clk)
		data_out_I = m_axis_data_tdata[15:0];
		data_out_Q = m_axis_data_tdata[31:16];
		$fwrite(fp_w,"%d %d\n", $signed(data_out_I), $signed(data_out_Q));
		w_n = w_n + 1;
	end
	$fclose(fp_w);
end