MSM6258: clock/rate selection

TODO.md

@@ -1,6 +1,5 @@
 # to-do for 0.6pre1
 
-- MSM6258 pitch and clock select
 - rewrite the system name detection function anyway
 - add another FM editor layout
 - if macros have release, note off should release them

src/engine/platform/msm6258.cpp

@@ -31,15 +31,25 @@ const char** DivPlatformMSM6258::getRegisterSheet() {
 }
 
 const char* DivPlatformMSM6258::getEffectName(unsigned char effect) {
+  switch (effect) {
+    case 0x20:
+      return "20xx: Set frequency divider (0-2)";
+      break;
+    case 0x21:
+      return "21xx: Select clock rate (0: full; 1: half)";
+      break;
+  }
   return NULL;
 }
 
 void DivPlatformMSM6258::acquire(short* bufL, short* bufR, size_t start, size_t len) {
-  for (size_t h=start; h<start+len; h++) {
   short* outs[2]={
-      &bufL[h],
+    &msmOut,
     NULL
   };
+  for (size_t h=start; h<start+len; h++) {
+    if (--msmClockCount<0) {
+      if (--msmDividerCount<=0) {
         if (!writes.empty()) {
           QueuedWrite& w=writes.front();
           switch (w.addr) {
@@ -74,8 +84,15 @@ void DivPlatformMSM6258::acquire(short* bufL, short* bufR, size_t start, size_t
         }
         
         msm->sound_stream_update(outs,1);
+        msmDividerCount=msmDivider;
+      }
+      msmClockCount=msmClock;
+    }
+    
     if (isMuted[0]) {
       bufL[h]=0;
+    } else {
+      bufL[h]=msmOut;
     }
 
     /*if (++updateOsc>=22) {
@@ -186,6 +203,14 @@ int DivPlatformMSM6258::dispatch(DivCommand c) {
         sampleBank=parent->song.sample.size()/12;
       }
       break;
+    case DIV_CMD_SAMPLE_FREQ:
+      rateSel=c.value&3;
+      rWrite(12,rateSel);
+      break;
+    case DIV_CMD_SAMPLE_MODE:
+      clockSel=c.value&1;
+      rWrite(8,clockSel);
+      break;
     case DIV_CMD_LEGATO: {
       break;
     }
@@ -215,6 +240,8 @@ void DivPlatformMSM6258::forceIns() {
   for (int i=0; i<1; i++) {
     chan[i].insChanged=true;
   }
+  rWrite(12,rateSel);
+  rWrite(8,clockSel);
 }
 
 void* DivPlatformMSM6258::getChanState(int ch) {
@@ -244,6 +271,14 @@ void DivPlatformMSM6258::poke(std::vector<DivRegWrite>& wlist) {
 void DivPlatformMSM6258::reset() {
   while (!writes.empty()) writes.pop();
   msm->device_reset();
+  msmClock=chipClock;
+  msmDivider=2;
+  msmDividerCount=0;
+  msmClock=0;
+  msmClockCount=0;
+  msmPan=3;
+  rateSel=0;
+  clockSel=0;
   if (dumpWrites) {
     addWrite(0xffffffff,0);
   }
@@ -317,15 +352,24 @@ void DivPlatformMSM6258::renderSamples() {
 }
 
 void DivPlatformMSM6258::setFlags(unsigned int flags) {
-  if (flags&1) {
+  switch (flags) {
+    case 3:
+      chipClock=8192000;
+      break;
+    case 2:
+      chipClock=8000000;
+      break;
+    case 1:
       chipClock=4096000;
-  } else {
+      break;
+    default:
       chipClock=4000000;
+      break;
   }
-  rate=chipClock/256;
+  rate=chipClock/128;
   for (int i=0; i<1; i++) {
     isMuted[i]=false;
-    oscBuf[i]->rate=rate/256;
+    oscBuf[i]->rate=rate;
   }
 }
 

src/engine/platform/msm6258.h

@@ -87,9 +87,11 @@ class DivPlatformMSM6258: public DivDispatch {
 
     unsigned char* adpcmMem;
     size_t adpcmMemLen;
-    unsigned char sampleBank, msmPan, msmDivider;
+    unsigned char sampleBank, msmPan, msmDivider, rateSel, msmClock, clockSel;
+    signed char msmDividerCount, msmClockCount;
+    short msmOut;
 
-    int delay, updateOsc, sample, samplePos, msmClock;
+    int delay, updateOsc, sample, samplePos;
 
     bool extMode;
   

src/engine/sysDef.cpp

@@ -1975,7 +1975,21 @@ void DivEngine::registerSystems() {
     {"Sample"},
     {"PCM"},
     {DIV_CH_PCM},
-    {DIV_INS_AMIGA}
+    {DIV_INS_AMIGA},
+    {},
+    [this](int ch, unsigned char effect, unsigned char effectVal) -> bool {
+      switch (effect) {
+        case 0x20: // select rate
+          dispatchCmd(DivCommand(DIV_CMD_SAMPLE_FREQ,ch,effectVal));
+          break;
+        case 0x21: // select clock
+          dispatchCmd(DivCommand(DIV_CMD_SAMPLE_MODE,ch,effectVal));
+          break;
+        default:
+          return false;
+      }
+      return true;
+    }
   );
 
   sysDefs[DIV_SYSTEM_YMZ280B]=new DivSysDef(

src/gui/sysConf.cpp

@@ -415,6 +415,22 @@ void FurnaceGUI::drawSysConf(int chan, DivSystem type, unsigned int& flags, bool
       }
       break;
     }
+    case DIV_SYSTEM_MSM6258: {
+      ImGui::Text("Clock rate:");
+      if (ImGui::RadioButton("4MHz",flags==0)) {
+        copyOfFlags=0;
+      }
+      if (ImGui::RadioButton("4.096MHz",flags==1)) {
+        copyOfFlags=1;
+      }
+      if (ImGui::RadioButton("8MHz (X68000)",flags==2)) {
+        copyOfFlags=2;
+      }
+      if (ImGui::RadioButton("8.192MHz",flags==3)) {
+        copyOfFlags=3;
+      }
+      break;
+    }
     case DIV_SYSTEM_MSM6295: {
       ImGui::Text("Clock rate:");
       if (ImGui::RadioButton("1MHz",flags==0)) {