added or.sv

wally-pipelined/src/generic/or.sv

@@ -0,0 +1,49 @@
+///////////////////////////////////////////
+// or.sv
+//
+// Written: David_Harris@hmc.edu 13 July 2021
+// Modified: 
+//
+// Purpose: Various flavors of multiplexers
+// 
+// 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"
+/* verilator lint_off DECLFILENAME */
+/* verilator lint_off UNOPTFLAT */
+
+// perform an OR of all the rows in an array, producing one output for each column
+// equivalent to assign y = a.or
+module or_rows #(parameter ROWS = 8, COLS=2) (
+  input  var logic [COLS-1:0] a[ROWS-1:0],
+  output logic [COLS-1:0] y); 
+
+  logic [COLS-1:0] mid[ROWS-1:0];
+  genvar row, col;
+  generate
+      for (col = 0; col < COLS; col++) begin
+          assign mid[1][col] = a[0][col] | a[1][col];
+          for (row=2; row < ROWS; row++)
+            assign mid[row][col] = mid[row-1][col] | a[row][col];
+          assign y[col] = mid[ROWS-1][col];
+      end
+  endgenerate
+endmodule
+
+/* verilator lint_on UNOPTFLAT */
+/* verilator lint_on DECLFILENAME */