-
-"""
-
- always @(posedge clk) begin:main_block
- if(reset) begin
- reset_to_initial();
- disable main_block;
- end
- case(fetch_output_state)
- `fetch_output_state_empty: begin
- end
- `fetch_output_state_trap: begin
- handle_trap();
- end
- `fetch_output_state_valid: begin:valid
- if((fetch_action == `fetch_action_error_trap) | (fetch_action == `fetch_action_noerror_trap)) begin
- handle_trap();
- end
- else if((decode_action & `decode_action_load) != 0) begin
- if(~memory_interface_rw_wait)
- write_register(decoder_rd, loaded_value);
- end
- else if((decode_action & `decode_action_op_op_imm) != 0) begin
- write_register(decoder_rd, alu_result);
- end
- else if((decode_action & `decode_action_lui_auipc) != 0) begin
- write_register(decoder_rd, lui_auipc_result);
- end
- else if((decode_action & (`decode_action_jal | `decode_action_jalr)) != 0) begin
- write_register(decoder_rd, fetch_output_pc + 4);
- end
- else if((decode_action & `decode_action_csr) != 0) begin:csr
- reg [31:0] csr_output_value;
- reg [31:0] csr_written_value;
- csr_output_value = 32'hXXXXXXXX;
- csr_written_value = 32'hXXXXXXXX;
- case(csr_number)
- `csr_cycle: begin
- csr_output_value = cycle_counter[31:0];
- end
- `csr_time: begin
- csr_output_value = time_counter[31:0];
- end
- `csr_instret: begin
- csr_output_value = instret_counter[31:0];
- end
- `csr_cycleh: begin
- csr_output_value = cycle_counter[63:32];
- end
- `csr_timeh: begin
- csr_output_value = time_counter[63:32];
- end
- `csr_instreth: begin
- csr_output_value = instret_counter[63:32];
- end
- `csr_mvendorid: begin
- csr_output_value = mvendorid;
- end
- `csr_marchid: begin
- csr_output_value = marchid;
- end
- `csr_mimpid: begin
- csr_output_value = mimpid;
- end
- `csr_mhartid: begin
- csr_output_value = mhartid;
- end
- `csr_misa: begin
- csr_output_value = misa;
- end
- `csr_mstatus: begin
- csr_output_value = make_mstatus(mstatus_tsr,
- mstatus_tw,
- mstatus_tvm,
- mstatus_mxr,
- mstatus_sum,
- mstatus_mprv,
- mstatus_xs,
- mstatus_fs,
- mstatus_mpp,
- mstatus_spp,
- mstatus_mpie,
- mstatus_spie,
- mstatus_upie,
- mstatus_mie,
- mstatus_sie,
- mstatus_uie);
- csr_written_value = evaluate_csr_funct3_operation(decoder_funct3, csr_output_value, csr_input_value);
- if(csr_writes) begin
- mstatus_mpie = csr_written_value[7];
- mstatus_mie = csr_written_value[3];
- end
- end
- `csr_mie: begin
- csr_output_value = 0;
- csr_output_value[11] = mie_meie;
- csr_output_value[9] = mie_seie;
- csr_output_value[8] = mie_ueie;
- csr_output_value[7] = mie_mtie;
- csr_output_value[5] = mie_stie;
- csr_output_value[4] = mie_utie;
- csr_output_value[3] = mie_msie;
- csr_output_value[1] = mie_ssie;
- csr_output_value[0] = mie_usie;
- csr_written_value = evaluate_csr_funct3_operation(decoder_funct3, csr_output_value, csr_input_value);
- if(csr_writes) begin
- mie_meie = csr_written_value[11];
- mie_mtie = csr_written_value[7];
- mie_msie = csr_written_value[3];
- end
- end
- `csr_mtvec: begin
- csr_output_value = mtvec;
- end
- `csr_mscratch: begin
- csr_output_value = mscratch;
- csr_written_value = evaluate_csr_funct3_operation(decoder_funct3, csr_output_value, csr_input_value);
- if(csr_writes)
- mscratch = csr_written_value;
- end
- `csr_mepc: begin
- csr_output_value = mepc;
- csr_written_value = evaluate_csr_funct3_operation(decoder_funct3, csr_output_value, csr_input_value);
- if(csr_writes)
- mepc = csr_written_value;
- end
- `csr_mcause: begin
- csr_output_value = mcause;
- csr_written_value = evaluate_csr_funct3_operation(decoder_funct3, csr_output_value, csr_input_value);
- if(csr_writes)
- mcause = csr_written_value;
- end
- `csr_mip: begin
- csr_output_value = 0;
- csr_output_value[11] = mip_meip;
- csr_output_value[9] = mip_seip;
- csr_output_value[8] = mip_ueip;
- csr_output_value[7] = mip_mtip;
- csr_output_value[5] = mip_stip;
- csr_output_value[4] = mip_utip;
- csr_output_value[3] = mip_msip;
- csr_output_value[1] = mip_ssip;
- csr_output_value[0] = mip_usip;
- end
- endcase
- if(csr_reads)
- write_register(decoder_rd, csr_output_value);
- end
- else if((decode_action & (`decode_action_fence | `decode_action_fence_i | `decode_action_store | `decode_action_branch)) != 0) begin
- // do nothing
- end
- end
- endcase
- end
-
-endmodule
-"""
-