system verilog typedef enum logic 三段式状态机
时间: 2023-06-28 10:08:01 浏览: 194
FPGA三段式状态机的思维陷阱.docx
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可以使用SystemVerilog中的typedef和enum结合来实现一个三段式状态机。下面是一个示例代码:
```
typedef enum logic [1:0] {STATE_IDLE, STATE_READY, STATE_BUSY} state_t;
module three_state_machine (
input wire clk,
input wire reset,
output reg [1:0] state
);
state_t next_state;
always @(posedge clk or posedge reset) begin
if (reset) begin
next_state <= STATE_IDLE;
end else begin
case (state)
STATE_IDLE: begin
// Transition to STATE_READY when input condition is met
if (input_condition) begin
next_state <= STATE_READY;
end else begin
next_state <= STATE_IDLE;
end
end
STATE_READY: begin
// Transition to STATE_BUSY when enable signal is high
if (enable_signal) begin
next_state <= STATE_BUSY;
end else begin
next_state <= STATE_READY;
end
end
STATE_BUSY: begin
// Transition to STATE_IDLE when operation is complete
if (operation_complete) begin
next_state <= STATE_IDLE;
end else begin
next_state <= STATE_BUSY;
end
end
endcase
end
// Update state register
state <= next_state;
end
endmodule
```
在这个三段式状态机中,我们定义了三个状态:STATE_IDLE,STATE_READY和STATE_BUSY。我们使用typedef将这个状态集合命名为state_t。
在模块中,我们有一个时钟输入,一个复位输入和一个状态输出。我们还有一个next_state变量,用于存储下一个状态。在时钟上升沿时,我们使用case语句根据当前状态更新下一个状态。最后,我们将next_state赋值给state,以便在下一个时钟上升沿时更新状态输出。
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