【Verilog/D8】

2023年8月5日

• [HDBits/Cs450/counter 2bc状态机](#HDBits/Cs450/counter 2bc状态机)
• 异步复位
• note
• [HDBits/Cs450/history shift](#HDBits/Cs450/history shift)
• HDBits/Cs450/gshare

HDBits/Cs450/counter 2bc状态机

Cs450/counter 2bc

LSB最低有效位

module top_module(
    input clk,
    input areset,
    input train_valid,
    input train_taken,
    output reg[1:0] state
);
    reg [1:0]next_state;
    

    always@(*)
        case(state)
            0:next_state=train_valid?(train_taken?1:0):0;
            1:next_state=train_valid?(train_taken?2:0):1;
            2:next_state=train_valid?(train_taken?3:1):2;
            3:next_state=train_valid?(train_taken?3:2):3;
        endcase
	always@(posedge clk or posedge areset)
            if(areset)
                state<=2'b1;
            else 
                state<=next_state;
endmodule

异步复位

always @(posedge clk or posedge areset)

if(areset)低电平有效

always @(posedge clk or negedge areset)

if(!areset)高电平有效

note

无语住了，之前relaunch仿真就会更新，几天没用vivado，relaunch就不更新仿真，没办法打开以前工程操作

没几句的代码，就是找不到原因，shit，搞了半天是复位问题

HDBits/Cs450/history shift

module top_module(
    input clk,
    input areset,
 
    input predict_valid,
    input predict_taken,
    output reg [31:0] predict_history,
 
    input train_mispredicted,
    input train_taken,
    input [31:0] train_history
);
    
    always @(posedge clk or posedge areset)
        if(areset)
            predict_history<=0;
    	else begin
           	if(train_mispredicted)
           		predict_history = {train_history[30:0],train_taken};
            else begin
           		if(predict_valid)
               		predict_history = {predict_history[30:0],predict_taken};
           		else
                    predict_history = predict_history;
            end
        end 
endmodule

HDBits/Cs450/gshare