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// license:BSD-3-Clause
// copyright-holders:Aaron Giles
#include "emu.h"
#include "ymf262.h"
DEFINE_DEVICE_TYPE(YMF262, ymf262_device, "ymf262", "YMF262 OPL3")
//*********************************************************
// YMF262 DEVICE
//*********************************************************
//-------------------------------------------------
// ymf262_device - constructor
//-------------------------------------------------
ymf262_device::ymf262_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock, device_type type) :
device_t(mconfig, type, tag, owner, clock),
device_sound_interface(mconfig, *this),
m_address(0),
m_stream(nullptr),
m_fm(*this)
{
}
//-------------------------------------------------
// read - handle a read from the device
//-------------------------------------------------
u8 ymf262_device::read(offs_t offset)
{
u8 result = 0x00;
switch (offset & 3)
{
case 0: // status port (A0=0, A1=0)
result = m_fm.status();
break;
default: // datasheet says anything else is not guaranteed
logerror("Unexpected read from YMF262 offset %d\n", offset & 3);
break;
}
return result;
}
//-------------------------------------------------
// write - handle a write to the register
// interface
//-------------------------------------------------
void ymf262_device::write(offs_t offset, u8 value)
{
switch (offset & 1)
{
case 0: // address ports - A1 references upper bank
m_address = value | (BIT(offset, 1) << 8);
// tests reveal that in compatibility mode, upper bit is masked
// except for register 0x105
if (m_fm.regs().newflag() == 0 && m_address != 0x105)
m_address &= 0xff;
break;
case 1: // data ports (A1 is ignored)
// force an update
m_stream->update();
// write to FM
m_fm.write(m_address, value);
break;
}
}
//-------------------------------------------------
// device_start - start of emulation
//-------------------------------------------------
void ymf262_device::device_start()
{
// create our stream
m_stream = stream_alloc(0, fm_engine::OUTPUTS, m_fm.sample_rate(clock()));
// initialize the FM engine
m_fm.init();
}
//-------------------------------------------------
// device_register_save - register for save state
//-------------------------------------------------
void ymf262_device::device_register_save(save_registrar &save)
{
// save our data
save.reg(NAME(m_address))
.reg(NAME(m_fm));
}
//-------------------------------------------------
// device_reset - start of emulation
//-------------------------------------------------
void ymf262_device::device_reset()
{
// reset the engines
m_fm.reset();
}
//-------------------------------------------------
// device_clock_changed - update if clock changes
//-------------------------------------------------
void ymf262_device::device_clock_changed()
{
m_stream->set_sample_rate(m_fm.sample_rate(clock()));
}
//-------------------------------------------------
// sound_stream_update - update the sound stream
//-------------------------------------------------
void ymf262_device::sound_stream_update(sound_stream &stream, std::vector<read_stream_view> const &inputs, std::vector<write_stream_view> &outputs)
{
// iterate over all target samples
for (int sampindex = 0; sampindex < outputs[0].samples(); sampindex++)
{
// clock the system
m_fm.clock(fm_engine::ALL_CHANNELS);
// update the FM content; clipping is unknown
s32 sums[fm_engine::OUTPUTS] = { 0 };
m_fm.output(sums, 0, 32767, fm_engine::ALL_CHANNELS);
// YMF262 outputs straight 16-bit data in 4 channels
for (int index = 0; index < fm_engine::OUTPUTS; index++)
outputs[index].put_int(sampindex, sums[index], 32768);
}
}
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