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Diffstat (limited to 'src/maker/tlv/pseudo_rand.m4out.tlv')
-rwxr-xr-x | src/maker/tlv/pseudo_rand.m4out.tlv | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/src/maker/tlv/pseudo_rand.m4out.tlv b/src/maker/tlv/pseudo_rand.m4out.tlv deleted file mode 100755 index cb0d6149..00000000 --- a/src/maker/tlv/pseudo_rand.m4out.tlv +++ /dev/null @@ -1,69 +0,0 @@ -\m4_TLV_version 1b: tl-x.org -\SV -/* -Copyright (c) 2014, Steven F. Hoover - -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. - * The name of Steven F. Hoover - may not 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 OWNER 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 pseudo_rand - #(parameter WIDTH=257) // Random vector width, to a max of 257. - (input logic clk, - input logic reset, - output logic [WIDTH-1:0] rand_vect - ); - -// Currently, this implements a Galois LFSR. -// TODO: It should be XORed with something else so it doesn't just shift. -// Using polynomials with maximal number of taps would have less regular shifting behavior. - -// Bits are numbered in the reverse of the traditional order. This puts the taps in the lower bit positions. - -// Choose optimal parameters for given WIDTH. -localparam LFSR_WIDTH = - (WIDTH <= 64) ? 64 : - (WIDTH <= 128) ? 128 : - (WIDTH <= 257) ? 257 : 0; // 257 enables a large non-power of two for replication on an irregular boundary. -// Polynomial source: http://www.eej.ulst.ac.uk/~ian/modules/EEE515/files/old_files/lfsr/lfsr_table.pdf -localparam [LFSR_WIDTH-1:0] LFSR_POLY = {{(LFSR_WIDTH-8){1'b0}}, - (LFSR_WIDTH == 64) ? 8'b00011011 : - (LFSR_WIDTH == 128) ? 8'b10000111 : - (LFSR_WIDTH == 257) ? 8'b11000101 : 8'b0}; - -bit [256:0] SEED = 257'h0_7163e168_713d5431_6684e132_5cd84848_f3048b46_76874654_0c45f864_04e4684a; - - - -\TLV - |default - @0 - $reset = reset; - @1 - $lfsr[LFSR_WIDTH-1:0] = $reset ? *SEED : {$lfsr#+1[LFSR_WIDTH-2:0], 1'b0} ^ ({LFSR_WIDTH{$lfsr#+1[LFSR_WIDTH-1]}} & *LFSR_POLY); - @2 - *rand_vect = $lfsr[WIDTH-1:0]; - -\SV - -endmodule |