/////////////////////////////////////////// // extend.sv // // Written: David_Harris@hmc.edu 9 January 2021 // Modified: // // Purpose: // // A component of the Wally configurable RISC-V project. // // Copyright (C) 2021 Harvey Mudd College & Oklahoma State University // // Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation // files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, // modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software // is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES // OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS // BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT // OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. /////////////////////////////////////////// `include "wally-macros.sv" module extend #(parameter XLEN=32) ( input logic [31:7] instr, input logic [2:0] immsrc, output logic [XLEN-1:0] immext); always_comb case(immsrc) // I-type 3'b000: immext = {{(XLEN-12){instr[31]}}, instr[31:20]}; // S-type (stores) 3'b001: immext = {{(XLEN-12){instr[31]}}, instr[31:25], instr[11:7]}; // B-type (branches) 3'b010: immext = {{(XLEN-12){instr[31]}}, instr[7], instr[30:25], instr[11:8], 1'b0}; // J-type (jal) 3'b011: immext = {{(XLEN-20){instr[31]}}, instr[19:12], instr[20], instr[30:21], 1'b0}; // U-type (lui, auipc) 3'b100: immext = {{(XLEN-31){instr[31]}}, instr[30:12], 12'b0}; /* verilator lint_off WIDTH */ default: immext = 'bx; // undefined /* verilator lint_on WIDTH */ endcase endmodule