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awacs_macrisc.cpp
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awacs_macrisc.cpp
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// license:BSD-3-Clause
// copyright-holders:R. Belmont
/***************************************************************************
awacs_macrisc.cpp
AWACS/Screamer 16-bit audio I/O for "MacRisc" architecture Macs (PCI-based)
AWACS and Screamer are audio CODECs that comply with a specification.
Data transfer to and from them is done in terms of serial frames.
Screamer is back-compatible with AWACS but supports more mixer inputs and
better power management.
***************************************************************************/
#include "emu.h"
#include "awacs_macrisc.h"
#define LOG_REGISTERS (1U << 1)
#define VERBOSE (0)
#include "logmacro.h"
constexpr u16 REGISTER_1_MUTE = 0x100;
// device type definition
DEFINE_DEVICE_TYPE(AWACS_MACRISC, awacs_macrisc_device, "awacsmr", "AWACS MacRisc audio I/O")
DEFINE_DEVICE_TYPE(SCREAMER, screamer_device, "screamer", "Screamer audio I/O")
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// awacs_macrisc_device - constructor
//-------------------------------------------------
awacs_macrisc_device::awacs_macrisc_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, type, tag, owner, clock)
, device_sound_interface(mconfig, *this)
, m_output_cb(*this, 0)
, m_input_cb(*this)
, m_stream(nullptr)
{
}
awacs_macrisc_device::awacs_macrisc_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: awacs_macrisc_device(mconfig, AWACS_MACRISC, tag, owner, clock)
{
}
screamer_device::screamer_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: awacs_macrisc_device(mconfig, SCREAMER, tag, owner, clock)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void awacs_macrisc_device::device_start()
{
// create the stream
m_stream = stream_alloc(0, 2, clock()/1024, STREAM_SYNCHRONOUS);
save_item(NAME(m_phase));
save_item(NAME(m_active));
save_item(NAME(m_registers));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void awacs_macrisc_device::device_reset()
{
m_phase = 0;
m_active = ACTIVE_OUT; // AWACS is always running, Screamer has a real enable/disable bit
m_registers[1] = REGISTER_1_MUTE;
m_stream->set_sample_rate(clock() / 1024);
}
void screamer_device::device_reset()
{
awacs_macrisc_device::device_reset();
m_active = 0;
}
//-------------------------------------------------
// sound_stream_update - handle update requests for
// our sound stream
//-------------------------------------------------
void awacs_macrisc_device::sound_stream_update(sound_stream &stream, std::vector<read_stream_view> const &inputs, std::vector<write_stream_view> &outputs)
{
// if we're active and not muted
if ((m_active & ACTIVE_OUT) && !(m_registers[1] & REGISTER_1_MUTE))
{
const s16 atten_L = 0xf - ((m_registers[2] >> 6) & 0xf);
const s16 atten_R = 0xf - (m_registers[2] & 0xf);
const u32 data = swapendian_int32(m_output_cb(m_phase));
const s16 l_raw = (s16)(data >> 16);
const s16 r_raw = (s16)(data & 0xffff);
const s32 left = ((s32)l_raw * atten_L) >> 4;
const s32 right = ((s32)r_raw * atten_R) >> 4;
outputs[0].put_int(0, left, 32768);
outputs[1].put_int(0, right, 32768);
}
else
{
outputs[0].put_int(0, 0, 32768);
outputs[1].put_int(0, 0, 32768);
}
m_phase = (m_phase + 1) & 0xfff;
}
uint32_t awacs_macrisc_device::read_macrisc(offs_t offset)
{
LOGMASKED(LOG_REGISTERS, "read AWACS @ %x\n", offset);
switch (offset)
{
case 0: // Audio Control
return 0;
case 4: // Audio CODEC Control
return 0;
case 8: // Audio CODEC Status
return 0x314000; // Screamer info
}
return 0;
}
void awacs_macrisc_device::write_macrisc(offs_t offset, uint32_t data)
{
static const int rates[8] = { 512, 768, 1024, 1280, 1536, 2048, 2560, 3072 };
LOGMASKED(LOG_REGISTERS, "%s: %08x @ %x\n", tag(), data, offset*4);
switch (offset)
{
case 0: // Audio Control
m_stream->set_sample_rate(clock() / rates[(data >> 8) & 7]);
LOG("%s: sample rate to %d Hz\n", tag(), clock() / rates[(data >> 8) & 7]);
break;
case 4: // Audio CODEC Control
{
int subframe = (data >> 22) & 0x3;
int codec_addr = (data >> 12) & 0xfff;
int codec_data = (data & 0xfff);
LOGMASKED(LOG_REGISTERS, "%s: CODEC control: %x to addr %x (subframe %d)\n", tag(), codec_data, codec_addr, subframe);
m_registers[codec_addr] = codec_data;
}
break;
case 8: // Audio CODEC Status
break;
case 12: // Byte swap
printf("CODEC byte swap: %08x\n", data);
break;
}
}
// Screamer
uint32_t screamer_device::read_macrisc(offs_t offset)
{
switch (offset)
{
case 0: // Audio Control
return 0;
case 4: // Audio CODEC Control
return 0;
case 8: // Audio CODEC Status
return swapendian_int32((0x40 << 8) | // indicate CODEC is present
(1 << 16) | // manufacturer is Crystal Semiconductor
(3 << 20)); // CODEC version 3 (Screamer)
}
return 0;
}
void screamer_device::write_macrisc(offs_t offset, uint32_t data)
{
awacs_macrisc_device::write_macrisc(offset, data);
// if IDLE bit is off, we're active
if (!BIT(m_registers[6], 1))
{
m_active |= ACTIVE_OUT;
}
else
{
m_active &= ~ACTIVE_OUT;
}
LOG("%s: Playback %s reg 6 %x)\n", tag(), !BIT(m_registers[6], 1) ? "on" : "off", m_registers[6]);
}