update JT12

rtl/sound/jt12/jt12_dout.v

@@ -0,0 +1,47 @@
+/* This file is part of JT12.
+
+ 
+    JT12 program 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 program 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: 21-03-2019
+*/
+
+module jt12_dout(
+    // input             rst_n,
+    input             clk,        // CPU clock
+    input             flag_A,
+    input             flag_B,
+    input             busy,
+    input      [5:0]  adpcma_flags,
+    input             adpcmb_flag,
+    input      [7:0]  psg_dout,
+    input      [1:0]  addr,
+    output reg [7:0]  dout
+);
+
+parameter use_ssg=0, use_adpcm=0;
+
+always @(posedge clk) begin
+    casez( addr )
+        2'b00: dout <= {busy, 5'd0, flag_B, flag_A }; // YM2203
+        2'b01: dout <= (use_ssg  ==1) ? psg_dout : {busy, 5'd0, flag_B, flag_A };
+        2'b1?: dout <= (use_adpcm==1) ?
+            { adpcmb_flag, 1'b0, adpcma_flags } :
+            { busy, 5'd0, flag_B, flag_A };
+    endcase
+end
+
+endmodule // jt12_dout