‘壹’ 给予FPGA的RS编码器的VHDL编程源代码
只有Verilog HDL代码
RS编码的乘法器：根据伽罗华域运算规则设计乘法器。当系数为0时，乘法器的Verilog HDL代码如下：
mole mula_0(a,c);
input [5:0] a;
output [5:0] c;
reg [5:0] c;
always @(a)
begin
c[5]<=a[5];
c[4]<=a[4];
c[3]<=a[3];
c[2]<=a[2];
c[1]<=a[1];
c[0]<=a[0];
end
endmole
代码分析：
由于伽罗华域的加法是作异或运算，当系数为0时，乘积即为本身。
当系数为1时，乘法器的Verilog HDL 代码如下：
mole mula_1(a,c);
input [5:0] a;
output [5:0] c;
reg [5:0] c;
always @(a)
begin
c[5]<=a[4];
c[4]<=a[3];
c[3]<=a[2];
c[2]<=a[1];
c[1]<=a[5] ^ a[0];
c[0]<=a[5];
end
endmole
RS编码的乘法器，设计Verilog HDL代码如下：
mole rscode(clk, clr, start, datavalid, x, y);
input clk;
input clr;
input start;
input datavalid;
input [5:0] x;
output [5:0] y;
reg [5:0] y;
wire [5:0] mul0, mul1, mul2, mul3, mul4, mul5;
wire [5:0] mul6, mul7, mul8, mul9, mul10, mul11;
wire [5:0] mul12, mul13, mul14, mul15, mul16, mul17;
reg [5:0] r0, r1, r2, r3, r4, r5;
reg [5:9] r6, r7, r8, r9, r10, r11;
reg [5:0] r12, r13, r14, r15, r16, r17;
reg [5:0] databack;
//调用乘法器
mula_45 g0(.a(databack), .c(mul0));
mula_48 g1(.a(databack), .c(mul1));
mula_3 g2(.a(databack), .c(mul2));
mula_51 g3(.a(databack), .c(mul3));
mula_35 g4(.a(databack), .c(mul4));
mula_11 g5(.a(databack), .c(mul5));
mula_32 g6(.a(databack), .c(mul6));
mula_59 g7(.a(databack), .c(mul7));
mula_25 g8(.a(databack), .c(mul8));
mula_31 g9(.a(databack), .c(mul9));
mula_6 g10(.a(databack), .c(mul10));
mula_21 g11(.a(databack), .c(mul11));
mula_38 g12(.a(databack), .c(mul12));
mula_61 g13(.a(databack), .c(mul13));
mula_3 g14(.a(databack), .c(mul14));
mula_0 g15(.a(databack), .c(mul15));
mula_59 g16(.a(databack), .c(mul16));
mula_22 g17(.a(databack), .c(mul17));
always @(posedge clk)
begin
if(clr == 1'b0)
begin
r0 <= 6'd0;
r1 <= 6'd0;
r2 <= 6'd0;
r3 <= 6'd0;
r4 <= 6'd0;
r5 <= 6'd0;
r6 <= 6'd0;
r7 <= 6'd0;
r8 <= 6'd0;
r9 <= 6'd0;
r10 <= 6'd0;
r11 <= 6'd0;
r12 <= 6'd0;
r13 <= 6'd0;
r14 <= 6'd0;
r15 <= 6'd0;
r16 <= 6'd0;
r17 <= 6'd0;
end
else if(start == 1'b1) //作异或运算
begin
r0 <= mul0;
r1 <= r0 ^ mul1;
r2 <= r1 ^ mul2;
r3 <= r2 ^ mul1;
r4 <= r3 ^ mul1;
r5 <= r4 ^ mul1;
r6 <= r5 ^ mul1;
r7 <= r6 ^ mul1;
r8 <= r7 ^ mul1;
r9 <= r8 ^ mul1;
r10 <= r9 ^ mul1;
r11 <= r10 ^ mul1;
r12 <= r11 ^ mul1;
r13 <= r12 ^ mul1;
r14 <= r13 ^ mul1;
r15 <= r14 ^ mul1;
r16 <= r15 ^ mul1;
r17 <= r16 ^ mul1;
end
end
always @(datavalid or x or r17)
begin
if(datavalid == 1'b1)
begin
databack <= x ^ r17;
end
else
begin
databack <= 6'd0;
end
end
always @(datavalid or x or r17)
begin
if(datavalid == 1'b1) //输出数据
begin
y <= x;
end
else //输出检验码
begin
y <= r17;
end
end
endmole
‘贰’ 用VHDL语言编程~急~
1. signal cnt:std_logic_vector(4 downto 0);
process(clk)
if clk'event and clk='1' then
if cnt="2100" then
cnt<="1000";
jinwei<='1';
else cnt<=cnt+1;
end if ;
end if;
end process;
6、b(3)=1;b(0)=0