Update turbosound.

2025-07-19 07:11:22 +03:00 · 2020-05-11 23:43:24 +08:00
parent 5a66d5ec1c
commit c08d8479be
51 changed files with 4523 additions and 3446 deletions
--- a/rtl/sound/jt12/jt12_eg_ctrl.v
+++ b/rtl/sound/jt12/jt12_eg_ctrl.v
@ -0,0 +1,122 @@
+/*  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: 29-10-2018
+
+	*/
+
+module jt12_eg_ctrl(
+	input				keyon_now,
+	input				keyoff_now,
+	input		[2:0]	state_in,
+	input		[9:0]	eg,
+	// envelope configuration	
+	input		[4:0]	arate, // attack  rate
+	input		[4:0]	rate1, // decay   rate
+	input		[4:0]	rate2, // sustain rate
+	input		[3:0]	rrate,
+	input		[3:0]	sl,   // sustain level
+	// SSG operation
+	input				ssg_en,
+	input		[2:0]	ssg_eg,
+	// SSG output inversion
+	input				ssg_inv_in,
+	output reg			ssg_inv_out,
+
+	output reg	[4:0]	base_rate,
+	output reg	[2:0]	state_next,
+	output reg			pg_rst
+);
+
+localparam 	ATTACK = 3'b001, 
+			DECAY  = 3'b010, 
+			HOLD   = 3'b100,
+			RELEASE= 3'b000; // default state is release 
+
+// wire is_decaying = state_in[1] | state_in[2];
+
+reg		[4:0]	sustain;
+
+always @(*) 
+	if( sl == 4'd15 )
+		sustain = 5'h1f; // 93dB
+	else
+		sustain = {1'b0, sl};
+
+wire	ssg_en_out;
+reg		ssg_en_in, ssg_pg_rst;
+
+// aliases
+wire ssg_att  = ssg_eg[2];
+wire ssg_alt  = ssg_eg[1];
+wire ssg_hold = ssg_eg[0] & ssg_en;
+
+reg ssg_over;
+
+
+always @(*) begin
+	ssg_over = ssg_en && eg[9]; // eg >=10'h200
+	ssg_pg_rst = ssg_over && !( ssg_alt || ssg_hold );
+	pg_rst = keyon_now | ssg_pg_rst;
+end
+
+always @(*) 
+	casez ( { keyoff_now, keyon_now, state_in} )
+		5'b01_???: begin // key on
+			base_rate	= arate;
+			state_next	= ATTACK;
+			ssg_inv_out	= ssg_att & ssg_en;
+		end
+		{2'b00, ATTACK}: 
+			if( eg==10'd0 ) begin
+				base_rate	= rate1;
+				state_next	= DECAY;
+				ssg_inv_out	= ssg_inv_in;
+			end
+			else begin
+				base_rate	= arate;
+				state_next	= ATTACK;
+				ssg_inv_out	= ssg_inv_in;
+			end
+		{2'b00, DECAY}: begin
+			if( ssg_over ) begin
+				base_rate	= ssg_hold ? 5'd0 : arate;
+				state_next	= ssg_hold ? HOLD : ATTACK;
+				ssg_inv_out	= ssg_en & (ssg_alt ^ ssg_inv_in);
+			end
+			else begin
+				base_rate	=  eg[9:5] >= sustain ? rate2 : rate1;
+				state_next	= DECAY;
+				ssg_inv_out = ssg_inv_in;
+			end
+		end
+		{2'b00, HOLD}: begin
+			base_rate	= 5'd0;
+			state_next	= HOLD;
+			ssg_inv_out	= ssg_inv_in;
+		end
+		default: begin // RELEASE, note that keyoff_now==1 will enter this state too
+			base_rate	= { rrate, 1'b1 };
+			state_next	= RELEASE;	// release
+			ssg_inv_out	= 1'b0; // this can produce a glitch in the output
+				// But to release from SSG cannot be done nicely while
+				// inverting the ouput
+		end
+	endcase
+
+
+endmodule // jt12_eg_ctrl