Started Zbb

-Performs byte instructions (orc.b, rev8 (32/64))

pipelined/src/ieu/zbb.sv

@@ -0,0 +1,59 @@
+
+///////////////////////////////////////////
+// zbb.sv
+//
+// Written: Kevin Kim <kekim@hmc.edu> and Kip Macsai-Goren <kmacsaigoren@hmc.edu>
+// Created: 2 February 2023
+// Modified: 
+//
+// Purpose: RISC-V miscellaneous bit manipulation unit (subset of ZBB instructions)
+//
+// Documentation: RISC-V System on Chip Design Chapter ***
+// 
+// A component of the CORE-V-WALLY configurable RISC-V project.
+// 
+// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
+//
+// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+//
+// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
+// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
+// may obtain a copy of the License at
+//
+// https://solderpad.org/licenses/SHL-2.1/
+//
+// Unless required by applicable law or agreed to in writing, any work distributed under the 
+// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
+// either express or implied. See the License for the specific language governing permissions 
+// and limitations under the License.
+////////////////////////////////////////////////////////////////////////////////////////////////
+
+`include "wally-config.vh"
+
+module zbb #(parameter WIDTH=32) (
+  input  logic [WIDTH-1:0] A, B,       // Operands
+  input  logic [2:0]       Funct3,     // Indicates operation to perform
+  input  logic [6:0]       Funct7,     // Indicates operation to perform
+  output logic [WIDTH-1:0] ZBBResult); // ZBC result
+
+  logic [WIDTH-1:0] OrcBResult;
+  logic [WIDTH-1:0] Rev8Result;
+
+  genvar i;
+
+  for (i=0;i<WIDTH;i+=8) begin:loop
+    assign OrcBResult[i+7:i] = {8{|A[i+7:i]}};
+    assign Rev8Result[WIDTH-i:WIDTH-i-7] = A[i+7:i];
+  end
+
+  //can replace with structural mux by looking at bit 4 in rs2 field
+  always_comb begin 
+      case ({Funct7, Funct3, B})
+      15'b0010100_101_00111: ZBBResult = OrcBResult;
+      15'b0110100_101_11000: ZBBResult = Rev8Result;
+      15'b0110101_101_11000: ZBBResult = Rev8Result;
+      endcase
+  end
+
+
+endmodule