aboutsummaryrefslogtreecommitdiff
path: root/rtl/multiword/mw_comparator.v
diff options
context:
space:
mode:
Diffstat (limited to 'rtl/multiword/mw_comparator.v')
-rw-r--r--rtl/multiword/mw_comparator.v220
1 files changed, 0 insertions, 220 deletions
diff --git a/rtl/multiword/mw_comparator.v b/rtl/multiword/mw_comparator.v
deleted file mode 100644
index 756ee83..0000000
--- a/rtl/multiword/mw_comparator.v
+++ /dev/null
@@ -1,220 +0,0 @@
-//------------------------------------------------------------------------------
-//
-// mw_comparator.v
-// -----------------------------------------------------------------------------
-// Multi-word comparator.
-//
-// Authors: Pavel Shatov
-//
-// Copyright (c) 2015-2016, NORDUnet A/S
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// - Redistributions of source code must retain the above copyright notice,
-// this list of conditions and the following disclaimer.
-//
-// - Redistributions in binary form must reproduce the above copyright notice,
-// this list of conditions and the following disclaimer in the documentation
-// and/or other materials provided with the distribution.
-//
-// - Neither the name of the NORDUnet nor the names of its contributors may be
-// used to endorse or promote products derived from this software without
-// specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-// POSSIBILITY OF SUCH DAMAGE.
-//
-//------------------------------------------------------------------------------
-
-module mw_comparator
- (
- clk, rst_n,
- ena, rdy,
- xy_addr, x_din, y_din,
- cmp_l, cmp_e, cmp_g
- );
-
-
- //
- // Parameters
- //
- parameter WORD_COUNTER_WIDTH = 3;
- parameter OPERAND_NUM_WORDS = 8;
-
-
- //
- // Handy Numbers
- //
- localparam [WORD_COUNTER_WIDTH-1:0] WORD_INDEX_ZERO = 0;
- localparam [WORD_COUNTER_WIDTH-1:0] WORD_INDEX_LAST = OPERAND_NUM_WORDS - 1;
-
-
- //
- // Handy Functions
- //
- function [WORD_COUNTER_WIDTH-1:0] WORD_INDEX_PREV_OR_LAST;
- input [WORD_COUNTER_WIDTH-1:0] WORD_INDEX_CURRENT;
- begin
- WORD_INDEX_PREV_OR_LAST = (WORD_INDEX_CURRENT > WORD_INDEX_ZERO) ?
- WORD_INDEX_CURRENT - 1'b1 : WORD_INDEX_LAST;
- end
- endfunction
-
-
- //
- // Ports
- //
- input wire clk; // system clock
- input wire rst_n; // active-low async reset
-
- input wire ena; // enable input
- output wire rdy; // ready output
-
- output wire [WORD_COUNTER_WIDTH-1:0] xy_addr; // address of current X and Y words
- input wire [ 32-1:0] x_din; // current X word
- input wire [ 32-1:0] y_din; // current Y word
-
- output wire cmp_l; // X < Y ?
- output wire cmp_e; // X = Y ?
- output wire cmp_g; // X > Y ?
-
-
- //
- // Word Indices
- //
- reg [WORD_COUNTER_WIDTH-1:0] index_xy;
-
- reg reg_cmp_l;
- reg reg_cmp_e;
- reg reg_cmp_g;
-
-
- //
- // Output Mapping
- //
- assign xy_addr = index_xy;
-
- assign cmp_l = reg_cmp_l;
- assign cmp_e = reg_cmp_e;
- assign cmp_g = reg_cmp_g;
-
-
- //
- // FSM
- //
- localparam FSM_SHREG_WIDTH = 1 * OPERAND_NUM_WORDS + 3;
-
- reg [FSM_SHREG_WIDTH-1:0] fsm_shreg;
-
- assign rdy = fsm_shreg[0];
-
- wire [OPERAND_NUM_WORDS-1:0] fsm_shreg_dec_index_xy = fsm_shreg[FSM_SHREG_WIDTH - (0 * OPERAND_NUM_WORDS + 1) : FSM_SHREG_WIDTH - (1 * OPERAND_NUM_WORDS + 0)];
- wire [OPERAND_NUM_WORDS-1:0] fsm_shreg_calc_leg = fsm_shreg[FSM_SHREG_WIDTH - (0 * OPERAND_NUM_WORDS + 3) : FSM_SHREG_WIDTH - (1 * OPERAND_NUM_WORDS + 2)];
- wire fsm_shreg_calc_leg_last = fsm_shreg[FSM_SHREG_WIDTH - (1 * OPERAND_NUM_WORDS + 2)];
-
- wire dec_index_xy = |fsm_shreg_dec_index_xy;
- wire calc_leg = |fsm_shreg_calc_leg;
- wire calc_leg_last = fsm_shreg_calc_leg_last;
-
-
- always @(posedge clk or negedge rst_n)
- //
- if (rst_n == 1'b0)
- //
- fsm_shreg <= {{FSM_SHREG_WIDTH-1{1'b0}}, 1'b1};
- //
- else begin
- //
- if (rdy) fsm_shreg <= {ena, {FSM_SHREG_WIDTH-2{1'b0}}, ~ena};
- //
- else fsm_shreg <= {1'b0, fsm_shreg[FSM_SHREG_WIDTH-1:1]};
- //
- end
-
-
- //
- // Word Index Increment Logic
- //
- always @(posedge clk)
- //
- if (rdy) index_xy <= WORD_INDEX_LAST;
- else if (dec_index_xy) index_xy <= WORD_INDEX_PREV_OR_LAST(index_xy);
-
-
- //
- // 32-bit Subtractor
- //
- wire [31: 0] sub32_d_out;
- wire sub32_b_in;
- wire sub32_b_out;
-
- subtractor32_wrapper subtractor32_inst
- (
- .clk (clk),
-
- .a (x_din),
- .b (y_din),
-
- .d (sub32_d_out),
-
- .b_in (sub32_b_in),
- .b_out (sub32_b_out)
- );
-
-
- //
- // Borrow Masking Logic
- //
- reg sub32_b_mask;
-
- always @(posedge clk)
- //
- sub32_b_mask <= (index_xy == WORD_INDEX_LAST) ? 1'b1 : 1'b0;
-
- assign sub32_b_in = sub32_b_out & ~sub32_b_mask;
-
- //
- // Output Logic
- //
- wire cmp_unresolved = !(cmp_l || cmp_g);
-
- wire cmp_borrow_is_set = (sub32_b_out == 1'b1) ? 1'b1 : 1'b0;
- wire cmp_difference_is_nonzero = (sub32_d_out != 32'd0) ? 1'b1 : 1'b0;
-
- always @(posedge clk)
- //
- if (rdy) begin
- //
- if (ena) begin
- //
- reg_cmp_l <= 1'b0;
- reg_cmp_e <= 1'b0;
- reg_cmp_g <= 1'b0;
- //
- end
- //
- end else if (cmp_unresolved && calc_leg) begin
- //
- if ( cmp_borrow_is_set) reg_cmp_l <= 1'b1;
- if (!cmp_borrow_is_set && cmp_difference_is_nonzero) reg_cmp_g <= 1'b1;
- if (!cmp_borrow_is_set && !cmp_difference_is_nonzero && calc_leg_last) reg_cmp_e <= 1'b1;
- //
- end
-
-
-endmodule
-
-
-//------------------------------------------------------------------------------
-// End-of-File
-//------------------------------------------------------------------------------