学习yosys(一款开源综合器)

安装

sudo apt-get install yosys		#ubuntu22.04仓库里面是yosys-0.9
sudo install xdot

创建脚本show_rtl.ys

read_verilog cpu.v
hierarchy -top cpu
proc; opt; fsm; opt; memory; opt;
show -prefix cpu

调用脚本

yosys show_rtl.ys

verilog代码

module cpu(input clk,input [15:0]op,     //[15:11]指令 [10:8]目标Reg索引 [7:0]立即数或源Reg索引output [7:0]R0      // R0-R7组织成寄存器组,  方便用寄存器索引 选择
);reg[7:0]R[7:0];
assign R0 = R[0];
reg [7:0] in1,in2, out1;
always @ (*) beginin1 = R[op[10:8]];in2 = op[11]? R[op[2:0]] : op[7:0];
endalways @ (*) begin case(op[15:12])0: out1 = in2;          // ldr1: out1 = in1 + in2;    // add2: out1 = in1 - in2;    // sub3: out1 = in1 & in2;    // and4: out1 = in1 | in2;    // or5: out1 = (in1 == in2);  // cmpdefault: out1 = 0;endcase
end// 3-8译码器
wire [7:0]sel;
always @(*) begincase(op[10:8])3'b000: sel = 8'b0000_0001;3'b001: sel = 8'b0000_0010;3'b010: sel = 8'b0000_0100;3'b011: sel = 8'b0000_1000;3'b100: sel = 8'b0001_0000;3'b101: sel = 8'b0010_0000;3'b110: sel = 8'b0100_0000;3'b111: sel = 8'b1000_0000;endcase
endalways @(posedge clk) beginif(sel[0]) R[0]=out1;if(sel[1]) R[1]=out1;if(sel[2]) R[2]=out1;if(sel[3]) R[3]=out1;if(sel[4]) R[4]=out1;if(sel[5]) R[5]=out1;if(sel[6]) R[6]=out1;if(sel[7]) R[7]=out1;else  R[7]=R[7]+1;
endendmodule

生成RTL图