Update turbosound.

rtl/sound/jt12/jt12_pm.v

@@ -0,0 +1,62 @@
+/*  This file is part of jt12.
+
+    jt12 is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    jt12 is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with jt12.  If not, see <http://www.gnu.org/licenses/>.
+	
+	Author: Jose Tejada Gomez. Twitter: @topapate
+	Version: 1.0
+	Date: 14-10-2018
+	*/
+
+// altera message_off 10030
+
+`timescale 1ns / 1ps
+
+// This implementation follows that of Alexey Khokholov (Nuke.YKT) in C language.
+
+module jt12_pm (
+	input [4:0] lfo_mod,
+	input [10:0] fnum,
+	input [2:0] pms,
+	output reg signed [8:0] pm_offset
+);
+
+
+reg [7:0] pm_unsigned;
+reg [7:0] pm_base;
+reg [9:0] pm_shifted;
+
+wire [2:0] index = lfo_mod[3] ? (~lfo_mod[2:0]) : lfo_mod[2:0];
+
+reg [3:0] lfo_sh1_lut [0:63];
+reg [3:0] lfo_sh2_lut [0:63];
+reg [2:0] lfo_sh1, lfo_sh2;
+
+initial begin
+	$readmemh("lfo_sh1_lut.hex",lfo_sh1_lut);
+	$readmemh("lfo_sh2_lut.hex",lfo_sh2_lut);
+end
+
+always @(*) begin
+	lfo_sh1 = lfo_sh1_lut[{pms,index}][2:0];
+	lfo_sh2 = lfo_sh2_lut[{pms,index}][2:0];
+	pm_base = ({1'b0,fnum[10:4]}>>lfo_sh1) + ({1'b0,fnum[10:4]}>>lfo_sh2);
+	case( pms )
+		default: pm_shifted = { 2'b0, pm_base };
+		3'd6: pm_shifted = { 1'b0, pm_base, 1'b0 };
+		3'd7: pm_shifted = {       pm_base, 2'b0 };
+	endcase // pms
+	pm_offset = lfo_mod[4] ? (-{1'b0,pm_shifted[9:2]}) : {1'b0,pm_shifted[9:2]};
+end // always @(*)
+
+endmodule