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// license:GPL-2.0+
// copyright-holders:Matthew Conte
/*****************************************************************************
MAME/MESS NES APU CORE
Based on the Nofrendo/Nosefart NES RP2A03 sound emulation core written by
Matthew Conte (matt@conte.com) and redesigned for use in MAME/MESS by
Who Wants to Know? (wwtk@mail.com)
This core is written with the advise and consent of Matthew Conte and is
released under the GNU Public License.
*****************************************************************************
NES_APU.H
NES APU external interface.
*****************************************************************************/
#ifndef MAME_SOUND_NES_APU_H
#define MAME_SOUND_NES_APU_H
#pragma once
#include "nes_defs.h"
/* AN EXPLANATION
*
* The NES APU is actually integrated into the Nintendo processor.
* You must supply the same number of APUs as you do processors.
* Also make sure to correspond the memory regions to those used in the
* processor, as each is shared.
*/
class nesapu_device : public device_t,
public device_sound_interface
{
public:
nesapu_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
// configuration helpers
auto irq() { return m_irq_handler.bind(); }
auto mem_read() { return m_mem_read_cb.bind(); }
virtual void device_reset() override ATTR_COLD;
virtual void device_clock_changed() override;
u8 status_r();
void write(offs_t offset, u8 data);
protected:
nesapu_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock);
// device-level overrides
virtual void device_start() override ATTR_COLD;
// sound stream update overrides
virtual void sound_stream_update(sound_stream &stream) override;
virtual void update_lfsr(apu_t::noise_t &chan);
private:
/* GLOBAL CONSTANTS */
static constexpr unsigned SYNCS_MAX1 = 0x20;
static constexpr unsigned SYNCS_MAX2 = 0x80;
static constexpr u32 NTSC_APU_CLOCK = 21477272 / 12;
static constexpr u32 PAL_APU_CLOCK = 26601712 / 16;
// internal state
apu_t m_APU; /* Actual APUs */
u8 m_is_pal;
u32 m_samps_per_sync; /* Number of samples per vsync */
u32 m_vbl_times[SYNCS_MAX1]; /* VBL durations in samples */
u32 m_sync_times1[SYNCS_MAX1]; /* Samples per sync table */
u32 m_sync_times2[SYNCS_MAX2]; /* Samples per sync table */
sound_stream::sample_t m_square_lut[31]; // Non-linear Square wave output LUT
sound_stream::sample_t m_tnd_lut[16][16][128]; // Non-linear Triangle, Noise, DMC output LUT
sound_stream *m_stream;
devcb_write_line m_irq_handler;
devcb_read8 m_mem_read_cb;
emu_timer *m_frame_timer;
attotime m_frame_period;
u16 m_frame_clocks;
TIMER_CALLBACK_MEMBER(frame_timer_cb);
void calculate_rates();
void apu_square(apu_t::square_t *chan);
void apu_triangle(apu_t::triangle_t *chan);
void apu_noise(apu_t::noise_t *chan);
void apu_dpcm(apu_t::dpcm_t *chan);
};
class apu2a03_device : public nesapu_device
{
public:
apu2a03_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
protected:
virtual void update_lfsr(apu_t::noise_t &chan) override;
};
DECLARE_DEVICE_TYPE(NES_APU, nesapu_device)
DECLARE_DEVICE_TYPE(APU_2A03, apu2a03_device)
#endif // MAME_SOUND_NES_APU_H
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