// license:BSD-3-Clause
// copyright-holders:Ryan Holtz
/**********************************************************************
Phasor, an ATmega88-based demo by Linus Åkesson
**********************************************************************/
#include "emu.h"
#include "cpu/avr8/avr8.h"
#include "sound/dac.h"
#include "sound/volt_reg.h"
#include "screen.h"
#include "emupal.h"
#include "speaker.h"
#define MASTER_CLOCK 17734470
#define SAMPLES_PER_FRAME (355255)
class lft_phasor_state : public driver_device
{
public:
lft_phasor_state(const machine_config &mconfig, device_type type, const char *tag)
: driver_device(mconfig, type, tag)
, m_maincpu(*this, "maincpu")
, m_dac(*this, "dac")
, m_screen(*this, "screen")
, m_palette(*this, "palette")
{
}
void phasor(machine_config &config);
protected:
virtual void machine_start() override;
virtual void machine_reset() override;
void prg_map(address_map &map);
void data_map(address_map &map);
void io_map(address_map &map);
uint8_t port_r(offs_t offset);
void port_w(offs_t offset, uint8_t data);
void init_palette(palette_device &palette) const;
void video_update();
uint32_t screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
required_device<avr8_device> m_maincpu;
required_device<dac_byte_interface> m_dac;
required_device<screen_device> m_screen;
required_device<palette_device> m_palette;
enum port : uint8_t
{
PORT_A,
PORT_B,
PORT_C,
PORT_D,
PORT_COUNT
};
uint8_t m_ports[PORT_COUNT];
uint64_t m_last_cycles;
uint64_t m_frame_start_cycle;
uint8_t m_latched_sample;
bool m_in_blanking;
uint64_t m_blanking_start;
uint32_t m_sample_x;
uint32_t m_sample_y;
std::unique_ptr<uint8_t[]> m_samples;
};
//**************************************************************************
// GPIO
//**************************************************************************
uint8_t lft_phasor_state::port_r(offs_t offset)
{
return m_ports[offset];
}
void lft_phasor_state::port_w(offs_t offset, uint8_t data)
{
m_ports[offset] = data;
switch (offset)
{
case AVR8_IO_PORTB:
video_update();
break;
case AVR8_IO_PORTC:
m_dac->write(data & 0x3f);
break;
case AVR8_IO_PORTD:
//video_update();
m_latched_sample = data;
break;
}
}
//**************************************************************************
// MEMORY
//**************************************************************************
void lft_phasor_state::prg_map(address_map &map)
{
map(0x0000, 0x1fff).rom();
}
void lft_phasor_state::data_map(address_map &map)
{
map(0x0100, 0x04ff).ram();
}
void lft_phasor_state::io_map(address_map &map)
{
map(AVR8_IO_PORTA, AVR8_IO_PORTD).rw(FUNC(lft_phasor_state::port_r), FUNC(lft_phasor_state::port_w));
}
//**************************************************************************
// VIDEO
//**************************************************************************
void lft_phasor_state::init_palette(palette_device &palette) const
{
for (int i = 0; i < 0x10; i++)
{
uint8_t gray = (uint8_t)i;
gray |= gray << 4;
palette.set_pen_color(i, rgb_t(gray, gray, gray));
}
}
void lft_phasor_state::video_update()
{
const uint64_t cycles = machine().time().as_ticks(MASTER_CLOCK);
if (cycles == m_last_cycles)
return;
if (m_latched_sample == 0 && !m_in_blanking)
{
m_in_blanking = true;
m_blanking_start = cycles;
}
else if (m_latched_sample != 0 && m_in_blanking)
{
m_in_blanking = false;
const uint64_t blank_duration = cycles - m_blanking_start;
if (blank_duration < 80) // Approximate length of hblank
{
m_sample_y++;
m_sample_x = 0;
}
else
{
m_sample_y = 0;
m_sample_x = 0;
m_frame_start_cycle = machine().time().as_ticks(MASTER_CLOCK);
}
}
if (m_last_cycles < cycles && !m_in_blanking)
{
const uint8_t shift = (m_ports[PORT_B] & 4);
uint32_t sample_pix = m_sample_y * 1135 + m_sample_x;
for (uint64_t idx = m_last_cycles; idx < cycles && sample_pix < SAMPLES_PER_FRAME; idx++)
{
m_samples[sample_pix++] = (m_latched_sample >> shift) & 0x0f;
m_sample_x++;
}
}
m_last_cycles = cycles;
}
uint32_t lft_phasor_state::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
{
const pen_t *pens = m_palette->pens();
for(int y = 0; y < 313; y++)
{
uint32_t *dst = &bitmap.pix32(y);
uint8_t *src = &m_samples[y * 1135];
for(int x = 0; x < 1135; x++)
{
*dst++ = pens[*src++];
}
}
return 0;
}
//**************************************************************************
// MACHINE
//**************************************************************************
static INPUT_PORTS_START( empty_input )
INPUT_PORTS_END
void lft_phasor_state::machine_start()
{
m_samples = std::make_unique<uint8_t[]>(SAMPLES_PER_FRAME);
save_item(NAME(m_ports));
save_item(NAME(m_last_cycles));
save_item(NAME(m_frame_start_cycle));
save_item(NAME(m_latched_sample));
save_item(NAME(m_in_blanking));
save_item(NAME(m_blanking_start));
save_item(NAME(m_sample_x));
save_item(NAME(m_sample_y));
save_pointer(NAME(m_samples), SAMPLES_PER_FRAME);
}
void lft_phasor_state::machine_reset()
{
memset(m_ports, 0, PORT_COUNT);
m_frame_start_cycle = 0;
m_last_cycles = 0;
m_latched_sample = 0;
m_in_blanking = true;
m_blanking_start = 0;
m_sample_x = 0;
m_sample_y = 0;
memset(&m_samples[0], 0, SAMPLES_PER_FRAME);
}
void lft_phasor_state::phasor(machine_config &config)
{
ATMEGA88(config, m_maincpu, MASTER_CLOCK);
m_maincpu->set_addrmap(AS_PROGRAM, &lft_phasor_state::prg_map);
m_maincpu->set_addrmap(AS_DATA, &lft_phasor_state::data_map);
m_maincpu->set_addrmap(AS_IO, &lft_phasor_state::io_map);
m_maincpu->set_eeprom_tag("eeprom");
PALETTE(config, m_palette, FUNC(lft_phasor_state::init_palette), 0x10);
SCREEN(config, m_screen, SCREEN_TYPE_RASTER);
m_screen->set_raw(MASTER_CLOCK, 1135, 0, 1064, 313, 6, 310);
m_screen->set_screen_update(FUNC(lft_phasor_state::screen_update));
SPEAKER(config, "avr8").front_center();
voltage_regulator_device &vref(VOLTAGE_REGULATOR(config, "vref", 0));
vref.add_route(0, m_dac, 1.0, DAC_VREF_POS_INPUT);
vref.add_route(0, m_dac, -1.0, DAC_VREF_NEG_INPUT);
DAC_6BIT_R2R(config, m_dac, 0).add_route(0, "avr8", 0.5);
}
ROM_START( phasor )
ROM_REGION( 0x2000, "maincpu", 0 )
ROM_LOAD( "phasor.bin", 0x0000, 0x2000, CRC(300ef49b) SHA1(36b26137f5e8359dc9c2b746621a98bdd6634d2f) )
ROM_REGION( 0x200, "eeprom", 0 )
ROM_LOAD( "eeprom.raw", 0x0000, 0x0200, CRC(49036547) SHA1(d98c4d02771e80499c56dd71ad3d07597102f9b7) )
ROM_END
/* YEAR NAME PARENT COMPAT MACHINE INPUT CLASS INIT COMPANY FULLNAME */
CONS(2010, phasor, 0, 0, phasor, empty_input, lft_phasor_state, empty_init, u8"Linus Åkesson", "Phasor", MACHINE_IMPERFECT_GRAPHICS)