-
- assign output_instruction = delayed_instruction_valid ? delayed_instruction : memory_interface_fetch_data;
-
- self.sync += delayed_instruction_valid.eq(fetch_action == `fetch_action_wait)
-
- always @(posedge clk or posedge reset) begin
- if(reset) begin
- output_state <= `fetch_output_state_empty;
- end
- else begin
- case(fetch_action)
- `fetch_action_default,
- `fetch_action_ack_trap: begin
- if(memory_interface_fetch_valid) begin
- fetch_pc <= fetch_pc + 4;
- output_state <= `fetch_output_state_valid;
- end
- else begin
- fetch_pc <= mtvec;
- output_state <= `fetch_output_state_trap;
- end
- end
- `fetch_action_fence: begin
- fetch_pc <= output_pc + 4;
- output_state <= `fetch_output_state_empty;
- end
- `fetch_action_jump: begin
- fetch_pc <= target_pc;
- output_state <= `fetch_output_state_empty;
- end
- `fetch_action_error_trap,
- `fetch_action_noerror_trap: begin
- fetch_pc <= mtvec;
- output_state <= `fetch_output_state_empty;
- end
- `fetch_action_wait: begin
- fetch_pc <= fetch_pc;
- output_state <= `fetch_output_state_valid;
- end
- endcase
- end
- end
- endmodule
+ self.sync += output_state.eq(fetch_output_state_empty)
+
+ self.comb += If(delayed_instruction_valid,
+ output_instruction.eq(delayed_instruction)
+ ).Else(
+ output_instruction.eq(memory_interface_fetch_data)
+ )
+
+ self.sync += delayed_instruction_valid.eq(fetch_action ==
+ fetch_action_wait)
+
+ fc = {
+ fetch_action_ack_trap:
+ If(memory_interface_fetch_valid,
+ [fetch_pc.eq(fetch_pc + 4),
+ output_state.eq(fetch_output_state_valid)]
+ ).Else(
+ [fetch_pc.eq(mtvec),
+ output_state.eq(fetch_output_state_trap)]
+ ),
+ fetch_action_fence:
+ [ fetch_pc.eq(output_pc + 4),
+ output_state.eq(fetch_output_state_empty)
+ ],
+ fetch_action_jump:
+ [ fetch_pc.eq(target_pc),
+ output_state.eq(fetch_output_state_empty)
+ ],
+ fetch_action_error_trap,
+ [fetch_pc.eq(mtvec),
+ output_state.eq(fetch_output_state_empty)
+ ],
+ fetch_action_wait:
+ [fetch_pc.eq(fetch_pc),
+ output_state.eq(fetch_output_state_valid)
+ ]
+ }
+ fc[fetch_action_default] = fc[fetch_action_ack_trap]
+ fc[fetch_action_noerror_trap] = fc[fetch_action_error_trap]
+ self.sync += Case(fetch_action, fc).makedefault(fetch_action_default)
+