这是处理器的执行块。大多数代码仅供参考。
module Execution_Block(A, B, data_in, op_dec, flag_ex, ans_ex, data_out,
mem_en_dec, mem_rw_dec, mem_mux_sel_dec, RW_dec, clk, reset,
B_Bypass, mem_en_ex, mem_rw_ex, mem_mux_sel_ex, RW_ex);
//INPUTS
input [7:0] A, B, data_in;
input clk, reset, mem_en_dec, mem_rw_dec, mem_mux_sel_dec;
input [4:0] RW_dec;
input [4:0] op_dec;
//OUTPUTS
output [3:0] flag_ex;
output reg mem_en_ex, mem_rw_ex, mem_mux_sel_ex;
output reg [7:0] B_Bypass, ans_ex, data_out;
output reg [4:0] RW_ex;
//WIRES
wire [7:0] ans_temp, data_out_buff;
wire [7:0] W0, W1,W2, W3, W4, W5, W6, W7, W8, W9, W10, W11, W12, W13, W14, W15, W16, W17, W18, W19, W20,
W21, W22, W23, W24, W25, W26, W27, W28;
wire P;
wire [3:0]flag_temp;
wire [3:0]flag_hold_prev;
//ALU
assign W0 = (op_dec == 5'b00000) ? (A+B) : W1; //ADD
assign W1 = (op_dec == 5'b00001) ? (A+(~B+1)) : W2; //SUB
assign W2 = (op_dec == 5'b00010) ? (B) : W3; //MOV
assign W3 = (op_dec == 5'b00100) ? (A&B) : W4; //AND
assign W4 = (op_dec == 5'b00101) ? (A|B) : W5; //OR
assign W5 = (op_dec == 5'b00110) ? (A^B) : W6; //XOR
assign W6 = (op_dec == 5'b00111) ? (~B) : W7; //NOR
assign W7 = (op_dec == 5'b01000) ? (A+B) : W8; //ADI
assign W8 = (op_dec == 5'b01001) ? (A+(~B+1)) : W9; //SBI
assign W9 = (op_dec == 5'b01010) ? (B) : W10; //NVI
assign W10 = (op_dec == 5'b01100) ? (A&B) : W11; //ANI
assign W11 = (op_dec == 5'b01101) ? (A|B) : W12; //ORI
assign W12 = (op_dec == 5'b01110) ? (A^B) : W13; //XRI
assign W13 = (op_dec == 5'b01111) ? (~B) : W14; //NTI
assign W14 = (op_dec == 5'b10000) ? (ans_temp) : W15; //RET
assign W15 = (op_dec == 5'b10001) ? (ans_temp) : W16; //HLT
assign W16 = (op_dec == 5'b10100) ? (A) : W17; //LD
assign W17 = (op_dec == 5'b10101) ? (A) : W18; //ST
assign W18 = (op_dec == 5'b10110) ? (data_in) : W19; //IN
assign W19 = (op_dec == 5'b00111) ? (ans_temp) : W20; //OUT
assign W20 = (op_dec == 5'b11000) ? (ans_temp) : W21; //JMP
assign W21 = (op_dec == 5'b11001) ? (A<<B) : W22; //LS
assign W22 = (op_dec == 5'b11011) ? (A>>B) : W23; //RS
assign W23 = (op_dec == 5'b11011) ?
((A[2:0]==3'b000) ? B :
((A[2:0]==3'b001) ? {B[7], B[7:1]} :
((A[2:0]==3'b010) ? {B[7], B[7], B[7:2]} :
((A[2:0]==3'b011) ? {B[7], B[7], B[7], B[7:3]} :
((A[2:0]==3'b100) ? {B[7], B[7], B[7], B[7], B[7:4]} :
((A[2:0]==3'b101) ? {B[7], B[7], B[7], B[7], B[7], B[7:5]} :
((A[2:0]==3'b110) ? {B[7], B[7], B[7], B[7], B[7], B[7], B[7:6]} :
((A[2:0]==3'b111) ? {B[7], B[7], B[7], B[7], B[7], B[7], B[7], B[7]}: 0)))))))) : W24; //RSA
assign W24 = (op_dec == 5'b11100) ? (ans_temp) : W25; //JC
assign W25 = (op_dec == 5'b11101) ? (ans_temp) : W26; //JNC
assign W26 = (op_dec == 5'b11110) ? (ans_temp) : W27; //JZ
assign W27 = (op_dec == 5'b11111) ? (ans_temp) : W28; //JNZ
assign W28 = 8'b00000000;
//ANSWER TEMP
assign ans_temp = ((op_dec == 5'b00000) ? W0 : //ADD
((op_dec == 5'b00001) ? W1 : //SUB
((op_dec == 5'b00010) ? W2 : //MOV
((op_dec == 5'b00100) ? W3 : //AND
((op_dec == 5'b00101) ? W4 : //OR
((op_dec == 5'b00110) ? W5 : //XOR
((op_dec == 5'b00111) ? W6 : //NOT
((op_dec == 5'b01000) ? W7 : //ADI
((op_dec == 5'b01001) ? W8 : //SBI
((op_dec == 5'b01010) ? W9 : //MVI
((op_dec == 5'b01100) ? W10 : //ANI
((op_dec == 5'b01101) ? W11 : //ORI
((op_dec == 5'b01110) ? W12 : //XRI
((op_dec == 5'b01111) ? W13 : //NTI
((op_dec == 5'b10000) ? W14 : //RET
((op_dec == 5'b10001) ? W15 : //HLT
((op_dec == 5'b10100) ? W16 : //LD
((op_dec == 5'b10101) ? W17 : //ST
((op_dec == 5'b10110) ? W18 : //IN
((op_dec == 5'b10111) ? W19 : //OUT
((op_dec == 5'b11000) ? W20 : //JMP
((op_dec == 5'b11001) ? W21 : //LS
((op_dec == 5'b11010) ? W22 : //RS
((op_dec == 5'b11011) ? W23 : //RSA
((op_dec == 5'b11100) ? W24 : //JC
((op_dec == 5'b11101) ? W25 : //JNC
((op_dec == 5'b11110) ? W26 : //JZ
((op_dec == 5'b11111) ? W27 : W28)))))))))))))))))))))))))))); //JNZ
//FLAGS
//CARRY FLAG
assign flag_temp[0] = (A[7]&B[7])|| (A[6]&B[6])|| (A[5]&B[5])|| (A[4]&B[4])||
(A[3]&B[3])|| (A[2]&B[2])|| (A[1]&B[1])|| (A[0]&B[0]);
//ZERO FLAG
assign flag_temp[1] = (ans_temp)? 1 : 0;
//OVERFLOW FLAG
assign flag_temp[2] = (A[7]&B[7]) ^ (A[6]&B[6]);
//PARITY FLAG
//PARITY GENERATOR
assign P = ans_temp[7] ^ ans_temp[6] ^ ans_temp[5] ^ ans_temp[4] ^
ans_temp[3] ^ ans_temp[2] ^ ans_temp[1] ^ ans_temp[0];
//PARITY CHECKER
assign flag_temp[3] = ans_temp[7] ^ ans_temp[6] ^ ans_temp[5] ^ ans_temp[4] ^
ans_temp[3] ^ ans_temp[2] ^ ans_temp[1] ^ ans_temp[0] ^ P;
Xst有一个错误：528 - 单元（Execution_Block）上的多源信号（flag_ex）此信号连接到多个驱动器。
//ALL FLAGS AFFECTED: flag_temp[3:0]
//PARITY AND ZERO AFFECTED, RESET OTHER FLAGS: {flag_temp[3], 1'b0, flag_temp[1], 1'b0}
//RESET ALL FLAGS: 4'b0000
//HOLD PREVIOUS FLAG: flag_hold_prev
assign flag_temp= ((op_dec == 5'b00000) ? flag_temp[3:0] : //ADD
((op_dec == 5'b00001) ? flag_temp[3:0] : //SUB
((op_dec == 5'b00010) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //MOV
((op_dec == 5'b00100) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //AND
((op_dec == 5'b00101) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //OR
((op_dec == 5'b00110) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //XOR
((op_dec == 5'b00111) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //NOT
((op_dec == 5'b01000) ? flag_temp[3:0] : //ADI
((op_dec == 5'b01001) ? flag_temp[3:0] : //SBI
((op_dec == 5'b01010) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //MVI
((op_dec == 5'b01100) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //ANI
((op_dec == 5'b01101) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //ORI
((op_dec == 5'b01110) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //XRI
((op_dec == 5'b01111) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //NTI
((op_dec == 5'b10000) ? 4'b0000 : //RET
((op_dec == 5'b10001) ? 4'b0000 : //HLT
((op_dec == 5'b10100) ? flag_hold_prev : //LD
((op_dec == 5'b10101) ? flag_hold_prev : //ST
((op_dec == 5'b10110) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //IN
((op_dec == 5'b10111) ? flag_hold_prev : //OUT
((op_dec == 5'b11000) ? flag_hold_prev : //JMP
((op_dec == 5'b11001) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //LS
((op_dec == 5'b11010) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //RS
((op_dec == 5'b11011) ? {flag_temp[3], 1'b0, flag_temp[1], 1'b0} : //RSA
((op_dec == 5'b11100) ? flag_hold_prev : //JC
((op_dec == 5'b11101) ? flag_hold_prev : //JNC
((op_dec == 5'b11110) ? flag_hold_prev : //JZ
((op_dec == 5'b11111) ? flag_hold_prev : W28)))))))))))))))))))))))))))); //JNZ
assign flag_ex = flag_temp;
assign flag_hold_prev = flag_ex;
即使flag_ex只分配了一次。
assign data_out_buff = (op_dec == 5'b10111) ? A : W28;
//REGISTER
always@(posedge clk)
begin
if(reset == 1'b1) //RESET SIGNAL IS ON
begin
ans_ex <= 8'b00000000;
data_out <= 8'b00000000;
mem_en_ex <= 1'b0;
mem_rw_ex <= 1'b0;
mem_mux_sel_ex <= 1'b0;
RW_ex <= 5'b00000;
B_Bypass <= 8'b00000000;
end
else //RESET SIGNAL IS OFF
begin
ans_ex <= ans_temp;
data_out <= data_out_buff;
mem_en_ex <= mem_en_dec;
mem_rw_ex <= mem_rw_dec;
mem_mux_sel_ex <= mem_mux_sel_dec;
RW_ex <= RW_dec;
B_Bypass <= B;
end
end
endmodule
答案 0 :(得分：0)
flag_temp分配在两个单独的assign语句中。一旦分配了各个位，并且下次整个总线。这将导致合成器出现问题。
您可能会看到此错误，因为flag_temp有多个驱动程序，而这些驱动程序又分配给flag_ex。
//FLAGS
//CARRY FLAG
assign flag_temp[0] = (A[7]&B[7])|| (A[6]&B[6])|| (A[5]&B[5])|| (A[4]&B[4])||
(A[3]&B[3])|| (A[2]&B[2])|| (A[1]&B[1])|| (A[0]&B[0]);
//ZERO FLAG
assign flag_temp[1] = (ans_temp)? 1 : 0;
//OVERFLOW FLAG
assign flag_temp[2] = (A[7]&B[7]) ^ (A[6]&B[6]);
//PARITY FLAG
//PARITY GENERATOR
assign P = ans_temp[7] ^ ans_temp[6] ^ ans_temp[5] ^ ans_temp[4] ^
ans_temp[3] ^ ans_temp[2] ^ ans_temp[1] ^ ans_temp[0];
//PARITY CHECKER
assign flag_temp[3] = ans_temp[7] ^ ans_temp[6] ^ ans_temp[5] ^ ans_temp[4] ^
ans_temp[3] ^ ans_temp[2] ^ ans_temp[1] ^ ans_temp[0] ^ P;
2ns实例。
assign flag_temp= ((op_dec == 5'b00000) ? fl ....