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ym2612: some progress on operators

This commit is contained in:
beirich 2012-04-29 17:41:39 +00:00
parent 25c2e45da8
commit 239cb213f0
2 changed files with 126 additions and 35 deletions
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111
BizHawk.Emulation/Sound/YM2612.IO.cs
View File

@ -3,9 +3,9 @@ using System.Collections.Generic;
namespace BizHawk.Emulation.Sound
{
// We process TIMER writes, and also track BUSY status, immediately when writes come in.
// All other writes are queued up with a timestamp, so that we can sift through them when
// we're rendering audio for the frame.
// We process TIMER writes immediately when writes come in.
// All other writes are queued up with a timestamp, so that we
// can sift through them when we're rendering audio for the frame.
public partial class YM2612
{
@ -16,19 +16,6 @@ namespace BizHawk.Emulation.Sound
Queue<QueuedCommand> commands = new Queue<QueuedCommand>();
/*
I might share a little quirk I discovered a few days ago, while I was working through a list of random tests unrelated to the envelope generator. I was running a test to check whether
parts 1 and 2 had a separate address register, IE, whether you could write one address to $A00000 and another to $A00002, then write to each data port, and have the two writes go to two
different register addresses in each part. What I found was that not only do parts 1 and 2 not have a separate address register, they don't even have a separate data port.
It turns out that writing to an address register stores both the written address, and the part number of the address register you wrote to. You can then write to either the data port at
$A00001, or the data port at $A00003, and the write will go to the register number you wrote, within the part of the address register you wrote to. This means you can, for example, write
an address to $A00000, then write the data to $A00003, and the data will in fact be written to the part 1 register block, not the part 2 register block.
The simpler implementation would seem to be only storing the 8-bit address data that was written, and use the data port that received the write to determine which part to write to, but
it isn't implemented this way. Writing to the address register stores 9 bits of data, indicating both the target register address, and the part number. I don't think any emulator does
this correctly right now.
*/
public byte ReadStatus(int clock)
{
UpdateTimers(clock);
@ -76,7 +63,54 @@ this correctly right now.
Part2_WriteRegister(cmd.Register, cmd.Data);
}
// information on TIMER is on pg 6
static void GetChanOpP1(byte value, out int channel, out int oper)
{
value &= 15;
switch (value)
{
case 0: channel = 0; oper = 0; return;
case 4: channel = 0; oper = 2; return;
case 8: channel = 0; oper = 1; return;
case 12: channel = 0; oper = 3; return;
case 1: channel = 1; oper = 0; return;
case 5: channel = 1; oper = 2; return;
case 9: channel = 1; oper = 1; return;
case 13: channel = 1; oper = 3; return;
case 2: channel = 2; oper = 0; return;
case 6: channel = 2; oper = 2; return;
case 10: channel = 2; oper = 1; return;
case 14: channel = 2; oper = 3; return;
default: channel = -1; oper = -1; return;
}
}
static void GetChanOpP2(byte value, out int channel, out int oper)
{
value &= 15;
switch (value)
{
case 0: channel = 3; oper = 0; return;
case 4: channel = 3; oper = 2; return;
case 8: channel = 3; oper = 1; return;
case 12: channel = 3; oper = 3; return;
case 1: channel = 4; oper = 0; return;
case 5: channel = 4; oper = 2; return;
case 9: channel = 4; oper = 1; return;
case 13: channel = 4; oper = 3; return;
case 2: channel = 5; oper = 0; return;
case 6: channel = 5; oper = 2; return;
case 10: channel = 5; oper = 1; return;
case 14: channel = 5; oper = 3; return;
default: channel = -1; oper = -1; return;
}
}
void Part1_WriteRegister(byte register, byte value)
{
switch (register)
@ -89,9 +123,24 @@ this correctly right now.
//case 0x28: Console.WriteLine("Operator Key On/Off Ctrl {0:X2}", value); break;
case 0x2A: DacValue = value; break;
case 0x2B: DacEnable = (value & 0x80) != 0; break;
case 0x2C: throw new Exception("something wrote to ym2612 port $2C!"); //http://forums.sonicretro.org/index.php?showtopic=28589
case 0x2C: throw new Exception("something wrote to ym2612 port $2C!"); break;//http://forums.sonicretro.org/index.php?showtopic=28589
default:
int chan, oper;
GetChanOpP1(register, out chan, out oper);
if (chan < 0) break; // abort if invalid port number
switch (register & 0xF0)
{
case 0x30: Channels[chan].Operators[oper].Write_MUL_DT1(value); break;
case 0x40: Channels[chan].Operators[oper].Write_TL(value); break;
case 0x50: Channels[chan].Operators[oper].Write_AR_KS(value); break;
case 0x60: Channels[chan].Operators[oper].Write_DR_AM(value); break;
case 0x70: Channels[chan].Operators[oper].Write_SR(value); break;
case 0x80: Channels[chan].Operators[oper].Write_RR_SL(value); break;
case 0x90: Channels[chan].Operators[oper].Write_SSGEG(value); break;
}
break;
// TODO bleh the situation with op2/op3 confusing
// "In MAME OPN emulation code register pairs for multi-frequency mode are A6A2, ACA8, AEAA, ADA9".
//D7 - operator, which frequency defined by A6A2
@ -101,13 +150,6 @@ this correctly right now.
//Where D7=op4, D6=op3, D5=op2, and D4=op1. That matches the YM2608 document. At least that's confirmed then.
// PG4 has some info on frquency calculations
default:
/* if (register >= 0x30 && register < 0xA0)
Console.WriteLine("P1 FM Channel data write");
else
Console.WriteLine("P1 REG {0:X2} WRITE {1:X2}", register, value); */
break;
}
}
@ -115,10 +157,19 @@ this correctly right now.
{
// NOTE. Only first bank has multi-frequency CSM/Special mode. This mode can't work on CH6.
/*if (register >= 0x30 && register < 0xA0)
Console.WriteLine("P2 FM Channel data write");
else
Console.WriteLine("P2 REG {0:X2} WRITE {1:X2}", register, value);*/
int chan, oper;
GetChanOpP2(register, out chan, out oper);
if (chan < 0) return; // abort if invalid port number
switch (register & 0xF0)
{
case 0x30: Channels[chan].Operators[oper].Write_MUL_DT1(value); break;
case 0x40: Channels[chan].Operators[oper].Write_TL(value); break;
case 0x50: Channels[chan].Operators[oper].Write_AR_KS(value); break;
case 0x60: Channels[chan].Operators[oper].Write_DR_AM(value); break;
case 0x70: Channels[chan].Operators[oper].Write_SR(value); break;
case 0x80: Channels[chan].Operators[oper].Write_RR_SL(value); break;
case 0x90: Channels[chan].Operators[oper].Write_SSGEG(value); break;
}
}
public class QueuedCommand

50
BizHawk.Emulation/Sound/YM2612.Operator.cs
View File

@ -8,12 +8,12 @@ namespace BizHawk.Emulation.Sound
{
// External Settings
public int TL_TotalLevel;
public int SL_SustainLevel;
public int AR_AttackRate;
public int RS_RateScaling;
public int D1R_FirstDecayRate;
public int D2R_SecondDecayRate;
public int D1L_FirstDecayLevel;
public int DR_DecayRate;
public int SR_SustainRate;
public int RR_ReleaseRate;
public int KS_KeyScale;
public int SSG_EG;
public int DT1_Detune;
@ -24,7 +24,47 @@ namespace BizHawk.Emulation.Sound
public int Frequency;
// Internal State
// ...
public int PhaseCounter;
// I/O
public void Write_MUL_DT1(byte value)
{
MUL_Multiple = value & 15;
DT1_Detune = (value >> 4) & 7;
}
public void Write_TL(byte value)
{
TL_TotalLevel = value & 127;
}
public void Write_AR_KS(byte value)
{
AR_AttackRate = value & 31;
KS_KeyScale = value >> 6;
}
public void Write_DR_AM(byte value)
{
DR_DecayRate = value & 31;
AM_AmplitudeModulation = (value & 128) != 0;
}
public void Write_SR(byte value)
{
SR_SustainRate = value & 31;
}
public void Write_RR_SL(byte value)
{
RR_ReleaseRate = value & 15;
SL_SustainLevel = value >> 4;
}
public void Write_SSGEG(byte value)
{
SSG_EG = value & 15;
}
}
}
//TODO "the shape of the waves of the envelope changes in a exponential when attacking it, and it changes in the straight line at other rates."