a2o/dev/verilog/trilib/tri_pri.v

130 lines
3.8 KiB
Verilog

// © IBM Corp. 2020
// Licensed under the Apache License, Version 2.0 (the "License"), as modified by
// the terms below; you may not use the files in this repository except in
// compliance with the License as modified.
// You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
//
// Modified Terms:
//
// 1) For the purpose of the patent license granted to you in Section 3 of the
// License, the "Work" hereby includes implementations of the work of authorship
// in physical form.
//
// 2) Notwithstanding any terms to the contrary in the License, any licenses
// necessary for implementation of the Work that are available from OpenPOWER
// via the Power ISA End User License Agreement (EULA) are explicitly excluded
// hereunder, and may be obtained from OpenPOWER under the terms and conditions
// of the EULA.
//
// Unless required by applicable law or agreed to in writing, the reference design
// 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.
//
// Additional rights, including the ability to physically implement a softcore that
// is compliant with the required sections of the Power ISA Specification, are
// available at no cost under the terms of the OpenPOWER Power ISA EULA, which can be
// obtained (along with the Power ISA) here: https://openpowerfoundation.org.
`timescale 1 ns / 1 ns
// Description: Prioritizer
//
//*****************************************************************************
module tri_pri(
cond,
pri,
or_cond
);
parameter SIZE = 32; // Size of "cond", range 3 - 32
parameter REV = 0; // 0 = 0 is highest, 1 = 0 is lowest
parameter CMP_ZERO = 0; // 1 = include comparing cond to zero in pri vector, 0 = don't
input [0:SIZE-1] cond;
output [0:SIZE-1+CMP_ZERO] pri;
output or_cond;
// tri_pri
parameter s = SIZE - 1;
wire [0:s] l0;
wire [0:s] or_l1;
wire [0:s] or_l2;
wire [0:s] or_l3;
wire [0:s] or_l4;
wire [0:s] or_l5;
generate
begin
if (REV == 0)
begin
assign l0[0:s] = cond[0:s];
end
if (REV == 1)
begin
assign l0[0:s] = cond[s:0];
end
// Odd Numbered Levels are inverted
assign or_l1[0] = ~l0[0];
assign or_l1[1:s] = ~(l0[0:s - 1] | l0[1:s]);
if (s >= 2)
begin
assign or_l2[0:1] = ~or_l1[0:1];
assign or_l2[2:s] = ~(or_l1[2:s] & or_l1[0:s - 2]);
end
if (s < 2)
begin
assign or_l2 = ~or_l1;
end
if (s >= 4)
begin
assign or_l3[0:3] = ~or_l2[0:3];
assign or_l3[4:s] = ~(or_l2[4:s] | or_l2[0:s - 4]);
end
if (s < 4)
begin
assign or_l3 = ~or_l2;
end
if (s >= 8)
begin
assign or_l4[0:7] = ~or_l3[0:7];
assign or_l4[8:s] = ~(or_l3[8:s] & or_l3[0:s - 8]);
end
if (s < 8)
begin
assign or_l4 = ~or_l3;
end
if (s >= 16)
begin
assign or_l5[0:15] = ~or_l4[0:15];
assign or_l5[16:s] = ~(or_l4[16:s] | or_l4[0:s - 16]);
end
if (s < 16)
begin
assign or_l5 = ~or_l4;
end
//assert SIZE > 32 report "Maximum Size of 32 Exceeded!" severity error;
assign pri[0] = cond[0];
assign pri[1:s] = cond[1:s] & or_l5[0:s - 1];
if (CMP_ZERO == 1)
begin
assign pri[s + 1] = or_l5[s];
end
assign or_cond = ~or_l5[s];
end
endgenerate
//!! [fail; tri_pri; "Priority not zero or one hot!!"] : (pri1 ) <= not zero_or_one_hot(pri);
endmodule