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ymf271.cpp: added slot end status bits, fixes at least missing shots samples for Desert War [Angelo Salese]

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This commit is contained in:
angelosa 2017-09-17 02:57:10 +02:00
parent bd4ce51a1c
commit a0b2a6f719
2 changed files with 31 additions and 4 deletions
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31
src/devices/sound/ymf271.cpp
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@ -11,7 +11,7 @@
- A/L bit (alternate loop)
- EN and EXT Out bits
- Src B and Src NOTE bits
- statusreg Busy and End bits
- statusreg Busy flag
- timer register 0x11
- ch2/ch3 (4 speakers)
- PFM (FM using external PCM waveform)
@ -245,6 +245,28 @@ inline bool ymf271_device::check_envelope_end(YMF271Slot *slot)
return false;
}
// calculate status end disable/enable (Desert War shots relies on this)
inline void ymf271_device::calculate_status_end(int slotnum, bool state)
{
// guess: don't enable/disable if slot isn't a multiple of 4
if(slotnum & 3)
return;
/*
bit scheme is kinda twisted
status1 Busy End36 End24 End12 End0 ---- TimB TimA
status2 End44 End32 End20 End8 End40 End28 End16 End4
*/
uint8_t subbit = slotnum / 12;
uint8_t bankbit = ((slotnum % 12) >> 2);
if(state == false)
m_end_status &= ~(1 << (subbit+bankbit*4));
else
m_end_status |= (1 << (subbit+bankbit*4));
}
void ymf271_device::update_envelope(YMF271Slot *slot)
{
switch (slot->env_state)
@ -450,6 +472,7 @@ void ymf271_device::update_pcm(int slotnum, int32_t *mixp, int length)
if ((slot->stepptr>>16) > slot->endaddr)
{
slot->stepptr = slot->stepptr - ((uint64_t)slot->endaddr<<16) + ((uint64_t)slot->loopaddr<<16);
calculate_status_end(slotnum,true);
if ((slot->stepptr>>16) > slot->endaddr)
{
// overflow
@ -1003,6 +1026,7 @@ void ymf271_device::write_register(int slotnum, int reg, uint8_t data)
slot->active = 1;
calculate_step(slot);
calculate_status_end(slotnum,false);
init_envelope(slot);
init_lfo(slot);
slot->feedback_modulation0 = 0;
@ -1476,11 +1500,11 @@ READ8_MEMBER( ymf271_device::read )
switch (offset & 0xf)
{
case 0x0:
return m_status;
return m_status | ((m_end_status & 0xf) << 3);
case 0x1:
// statusreg 2
return 0;
return m_end_status >> 4;
case 0x2:
{
@ -1692,6 +1716,7 @@ void ymf271_device::init_state()
save_item(NAME(m_timerB));
save_item(NAME(m_irqstate));
save_item(NAME(m_status));
save_item(NAME(m_end_status));
save_item(NAME(m_enable));
save_item(NAME(m_ext_address));
save_item(NAME(m_ext_rw));

4
src/devices/sound/ymf271.h
View File

@ -119,7 +119,8 @@ private:
inline int get_internal_keycode(int block, int fns);
inline int get_external_keycode(int block, int fns);
inline bool check_envelope_end(YMF271Slot *slot);
inline void calculate_status_end(int slotnum, bool state);
// lookup tables
std::unique_ptr<int16_t[]> m_lut_waves[8];
std::unique_ptr<double[]> m_lut_plfo[4][8];
@ -141,6 +142,7 @@ private:
uint32_t m_timerB;
uint8_t m_irqstate;
uint8_t m_status;
uint16_t m_end_status;
uint8_t m_enable;
uint32_t m_ext_address;