最近写的一个SRAM控制器verilog格式不对的地方高人多指点

mengzhuhao · 发表于 2008-11-10 20:34

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最近写的一个SRAM控制器verilog格式不对的地方高人多指点
控制外部SRAM需要注意什么？
在代码风格上如何描述更稳定可靠呢？

module SRAM_TEST(
i_Reset_n,
i_Clock,
i_EN,
i_StepByStep,
i_WR_Control,
o_W_FullSign,
/* SRAM InteRFace */
o_Sram_add,
io_Sram_data,
o_Sram_CE_n,
o_Sram_WE_n,
o_Sram_OE_n,
o_Sram_UB_n,
o_Sram_LB_n,
/* Display */
o_HEX,
t_HEX);

input          i_Reset_n;
input          i_Clock;
input          i_EN;
input          i_StepByStep;
input       i_WR_Control;
output       o_W_FullSign;
/*SRAM Interface*/
output [17:0]  o_Sram_add;
inout [15:0]  io_Sram_data;
output       o_Sram_CE_n;
output       o_Sram_WE_n;
output       o_Sram_OE_n;
output       o_Sram_UB_n;
output       o_Sram_LB_n;
/* Display */
output [6:0]  o_HEX;
output [6:0]  t_HEX;

reg    [6:0]  o_HEX;
reg    [6:0]  t_HEX;
reg    [17:0] o_Sram_add;
reg    [3:0]  t_counter;
reg       o_Sram_CE_n;
reg       o_Sram_WE_n;
reg       o_Sram_OE_n;
reg       o_Sram_UB_n;
reg       o_Sram_LB_n;
reg    [15:0] Sram_data_in;
reg    [15:0] Sram_data_out;
reg             Counter_EN;
reg    [17:0] WADD_Counter;
reg    [17:0] RADD_Counter;
reg    [15:0] W_data;
reg             o_W_FullSign;
reg    [2:0]  Sram_State;
reg             i_StepByStep1;
reg             i_StepByStep2;
reg             i_StepByStep3;
reg             i_StepByStep4;
reg             i_WR_Control1;
reg             i_WR_Control2;
reg             i_WR_Control3;

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)
Counter_EN<=0;
  else begin
if(i_EN)
   Counter_EN<=0;
else
   Counter_EN<=~Counter_EN;
end

always @(posedge i_Clock or negedge i_Reset_n)begin
if(~i_Reset_n)begin
   i_StepByStep1<=1;
   i_StepByStep2<=1;
   i_StepByStep3<=1;
   i_StepByStep4<=0;
   i_WR_Control1<=1;
   i_WR_Control2<=1;
   i_WR_Control3<=1;
end
else begin
   i_StepByStep1<=i_StepByStep;
   i_StepByStep2<=i_StepByStep1;
   i_StepByStep3<=i_StepByStep2;
   i_StepByStep4<=(i_StepByStep2 ^ i_StepByStep3) & i_StepByStep3;
   i_WR_Control1<=i_WR_Control;
   i_WR_Control2<=i_WR_Control1;
   i_WR_Control3<=i_WR_Control2;
end
  end

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)begin
WADD_Counter<=0;
o_W_FullSign<=1;
end
  else begin
if(i_WR_Control3 &i_StepByStep4==1)
   if(WADD_Counter==15)begin
   WADD_Counter<=WADD_Counter;
   o_W_FullSign<=0;
   end
   else begin
   WADD_Counter<=WADD_Counter+1;
   o_W_FullSign<=o_W_FullSign;
   end
else begin
   WADD_Counter<=WADD_Counter;
   o_W_FullSign<=o_W_FullSign;
   end
end

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)begin
W_data<=0;
end
  else begin
if(i_WR_Control3 &i_StepByStep4==1)
   if(W_data==15)
   W_data<=W_data;
   else
   W_data<=W_data+1;
else
   W_data<=W_data;
end

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)
RADD_Counter<=15;
  else begin
if(i_StepByStep4==1 & ~i_WR_Control3)
   if(RADD_Counter==0)
   RADD_Counter<=15;
   else
   RADD_Counter<=RADD_Counter-1;
else
   RADD_Counter<=RADD_Counter;
end

parameter    IDLE       =3'b000;
parameter    READ       =3'b001;
parameter    WRITE       =3'b010;

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)begin
Sram_State<=IDLE;
o_Sram_add<={16{1'b0}};
Sram_data_in<={16{1'b0}};
Sram_data_out<={16{1'b0}};
o_Sram_CE_n<=1;
o_Sram_WE_n<=1;
o_Sram_OE_n<=1;
o_Sram_UB_n<=1;
o_Sram_LB_n<=1;
end
  else begin
case(Sram_State)
   IDLE:begin
   if(~i_EN)begin
      if(i_WR_Control3)begin
         Sram_State<=WRITE;
         o_Sram_add<=WADD_Counter;
         Sram_data_in<={16{1'bz}};
         Sram_data_out<=Sram_data_out;
         o_Sram_CE_n<=0;
         o_Sram_WE_n<=0;
         o_Sram_OE_n<=1;
         o_Sram_UB_n<=0;
         o_Sram_LB_n<=0;
      end
      else begin
         Sram_State<=READ;
         o_Sram_add<=RADD_Counter;
         Sram_data_in<=Sram_data_in;
         Sram_data_out<={16{1'bz}};
         o_Sram_CE_n<=0;
         o_Sram_WE_n<=1;
         o_Sram_OE_n<=0;
         o_Sram_UB_n<=0;
         o_Sram_LB_n<=0;
      end
      end
   else begin
      Sram_State<=IDLE;
      o_Sram_add<=0;
      Sram_data_in<={16{1'b0}};
      Sram_data_out<={16{1'b0}};
      o_Sram_CE_n<=1;
      o_Sram_WE_n<=1;
      o_Sram_OE_n<=1;
      o_Sram_UB_n<=1;
      o_Sram_LB_n<=1;
      end
   end
   READ:begin
   Sram_State<=IDLE;
   o_Sram_add<=RADD_Counter;
   Sram_data_in<=io_Sram_data;
   Sram_data_out<={16{1'bz}};
   o_Sram_CE_n<=0;
   o_Sram_WE_n<=1;
   o_Sram_OE_n<=0;
   o_Sram_UB_n<=0;
   o_Sram_LB_n<=0;
   end
   WRITE:begin
   Sram_State<=IDLE;
   o_Sram_add<=WADD_Counter;
   Sram_data_in<={16{1'bz}};
   Sram_data_out<=W_data;
   o_Sram_CE_n<=0;
   o_Sram_WE_n<=0;
   o_Sram_OE_n<=1;
   o_Sram_UB_n<=0;
   o_Sram_LB_n<=0;
   end
   default:begin
   Sram_State<=IDLE;
   o_Sram_add<=0;
   Sram_data_in<={16{1'bz}};
   Sram_data_out<={16{1'bz}};
   o_Sram_CE_n<=1;
   o_Sram_WE_n<=1;
   o_Sram_OE_n<=1;
   o_Sram_UB_n<=1;
   o_Sram_LB_n<=1;
   end
endcase
end
assign io_Sram_data=(i_WR_Control3)? Sram_data_out:{16{1'bz}};

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)
o_HEX<=7'b1000000;
  else begin
if(i_WR_Control3)
   case(Sram_data_out[3:0])
   4'b0000

_HEX<=7'b1000000;
4'b0001

_HEX<=7'b1111001;
4'b0010

_HEX<=7'b0100100;
   4'b0011:o_HEX<=7'b0110000;
   4'b0100:o_HEX<=7'b0011001;
   4'b0101:o_HEX<=7'b0010010;
   4'b0110:o_HEX<=7'b0000010;
   4'b0111:o_HEX<=7'b1111000;
   4'b1000:o_HEX<=7'b0000000;
   4'b1001:o_HEX<=7'b0010000;
   4'b1010:o_HEX<=7'b0001000;
   4'b1011:o_HEX<=7'b0000011;
   4'b1100:o_HEX<=7'b1000110;
   4'b1101:o_HEX<=7'b0100001;
   4'b1110:o_HEX<=7'b0000110;
   4'b1111:o_HEX<=7'b0001110;
   default:o_HEX<=7'b1000000;
   endcase
else
   o_HEX<=7'b1000000;
end

always @(posedge i_Clock or negedge i_Reset_n)
  if(~i_Reset_n)
t_HEX<=7'b1000000;
  else begin
case(Sram_data_in[3:0])
   4'b0000:t_HEX<=7'b1000000;
   4'b0001:t_HEX<=7'b1111001;
   4'b0010:t_HEX<=7'b0100100;
   4'b0011:t_HEX<=7'b0110000;
   4'b0100:t_HEX<=7'b0011001;
   4'b0101:t_HEX<=7'b0010010;
   4'b0110:t_HEX<=7'b0000010;
   4'b0111:t_HEX<=7'b1111000;
   4'b1000:t_HEX<=7'b0000000;
   4'b1001:t_HEX<=7'b0010000;
   4'b1010:t_HEX<=7'b0001000;
   4'b1011:t_HEX<=7'b0000011;
   4'b1100:t_HEX<=7'b1000110;
   4'b1101:t_HEX<=7'b0100001;
   4'b1110:t_HEX<=7'b0000110;
   4'b1111:t_HEX<=7'b0001110;
   default:t_HEX<=7'b1000000;
endcase
end

endmodule