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Diffstat (limited to 'rtl/multiword/mw_comparator.v')
-rw-r--r-- | rtl/multiword/mw_comparator.v | 220 |
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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 -//------------------------------------------------------------------------------ |