/////////////////////////////////////////// // intdivrestoringstep.sv // // Written: David_Harris@hmc.edu 2 October 2021 // Modified: // // Purpose: Restoring integer division using a shift register and subtractor // // 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-config.vh" module intdivrestoringstep( input logic [`XLEN-1:0] W, XQ, DAbsB, output logic [`XLEN-1:0] WOut, XQOut); logic [`XLEN-1:0] WShift, WPrime; logic qi, qib; assign {WShift, XQOut} = {W[`XLEN-2:0], XQ, qi}; assign {qib, WPrime} = {1'b0, WShift} + {1'b1, DAbsB} + 1; // subtractor, carry out determines quotient bit ***replace with add assign qi = ~qib; mux2 #(`XLEN) wrestoremux(WShift, WPrime, qi, WOut); endmodule