帮我看下这个代码有什么问题？为什么读不出高16位

只看该作者 · 2022-7-25 18:17

////////////////////////////////////////
/*
fsmc 总线去读取 data_read高位时无法读取出来，一直是0。

这个总线读取是正确的，低16位正确的，高16位读不出来。
就是 12'd151:和12'd154  读回来的是0值，不知道是和原因

*/

module code_top(
            clk_100,
   rst_n,
csn,
   rden,
   wren,
   CODE_A,
CODE_B,
CODE_Z,
address,
data_in,
   data_out
   );

assign wr = !(csn | wren);
assign rd = !(csn & rden);

input clk_100,rst_n,rden,wren;
input [3:0] CODE_A,CODE_B,CODE_Z;
input [11:0] address;
input [15:0] data_in;
output  [15:0] data_out;
input csn;
wire [33:0] code_data[3:0];
wire [15:0] z_counter[3:0];
reg [33:0] data_read[3:0];
reg [15:0] z_read[3:0];

////////////////

encode code_x(
                  .clk_100M(clk_100),
   .rst_n(rst_n),
   .A_in(CODE_A[0]),
   .B_in(CODE_B[0]),
   .Z_in(CODE_Z[0]),
   .code_data(code_data[0]),
   .z_counter(z_counter[0])
);

////////////

reg [15:0]DB_OUT;

reg [15:0]data_read_h;
always @(rd or !rst_n)
begin
   if(!rst_n)
   begin
               DB_OUT<=16'hzzzz;
               data_read_h<= 16'h0;
   end
   else
begin
case (address)

12'd150:
begin
DB_OUT  <=  data_read[0][17:2];
data_read_h<= data_read[0][33:18];
end
12'd151:
begin
DB_OUT  <=data_read_h; //x 16'd111;//
end
12'd152:DB_OUT  <= z_read[0];

12'd153:
begin
DB_OUT  <= data_read[1][17:2];
data_read_h<= data_read[1][33:18];
end
12'd154:
begin
DB_OUT  <=data_read_h;    //y code_data[1][33:18];//
end
12'd155:DB_OUT  <=z_read[1];

12'd156:
begin
DB_OUT  <= data_read[2][17:2];
data_read_h<= data_read[2][33:18];
end

default :
begin
DB_OUT <= 16'hzzzz;
     code_data_h <= 16'h0000;
end

endcase

end
end

assign data_out = rd ? DB_OUT : 16'hzzzz;

always@(posedge clk_100 or negedge rst_n)
begin
   if(!rst_n)
   begin
data_read[0] <= 33'd0;
data_read[1] <=  33'd0;
data_read[2] <=  33'd0;
data_read[3] <=  33'd0;
z_read[0] <=  16'd0;
z_read[1] <=  16'd0;
z_read[2] <=16'd0;
z_read[3] <= 16'd0;
//    code_data_h <= 16'h1;
   end
   else
   begin
data_read[0] <= code_data[0];
data_read[1] <= code_data[1];
data_read[2] <= code_data[2];
data_read[3] <= code_data[3];
z_read[0] <= z_counter[0];
z_read[1] <= z_counter[1];
z_read[2] <= z_counter[2];
z_read[3] <= z_counter[3];
end
end