apb从机verilog代码
时间: 2023-08-26 21:06:52 浏览: 62
以下是一个简单的 APB 从机的 Verilog 代码,仅供参考:
```verilog
module apb_slave (
input pclk,
input presetn,
input [31:0] paddr,
input psel,
input penable,
input [1:0] pwrite,
input [31:0] pwdata,
output reg [31:0] prdata,
output reg pready,
output reg pslverr
);
// 定义 APB 从机的状态机
localparam IDLE = 2'b00, READ = 2'b01, WRITE = 2'b10;
reg [1:0] state, next_state;
// 定义从机的寄存器,例如一个 32 位的控制寄存器
reg [31:0] control_reg;
// 在 IDLE 状态初始化一些值
always @(posedge pclk or negedge presetn) begin
if (!presetn) begin
state <= IDLE;
pslverr <= 1'b0;
control_reg <= 0;
end else begin
state <= next_state;
pslverr <= 1'b0;
end
end
// 定义状态机的转移逻辑
always @(*) begin
case (state)
IDLE: begin
if (psel && penable) begin
if (pwrite == 2'b01) begin
next_state = READ;
end else if (pwrite == 2'b10) begin
next_state = WRITE;
end
end else begin
next_state = IDLE;
end
end
READ: begin
next_state = IDLE;
end
WRITE: begin
next_state = IDLE;
end
default: next_state = IDLE;
endcase
end
// 定义从机的读写逻辑
always @(posedge pclk or negedge presetn) begin
if (!presetn) begin
prdata <= 0;
pready <= 1'b0;
end else begin
case (state)
IDLE: begin
pready <= 1'b1;
end
READ: begin
prdata <= control_reg;
pready <= 1'b1;
end
WRITE: begin
if (psel && penable) begin
control_reg <= pwdata;
pready <= 1'b1;
end else begin
pslverr <= 1'b1;
pready <= 1'b0;
end
end
default: begin
pslverr <= 1'b1;
pready <= 1'b0;
end
endcase
end
end
endmodule
```
需要注意的是,这只是一个简单的示例代码,实际的 APB 从机的设计可能会更加复杂。