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Diffstat (limited to 'src/devices/machine/adc0844.cpp')
-rw-r--r-- | src/devices/machine/adc0844.cpp | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/src/devices/machine/adc0844.cpp b/src/devices/machine/adc0844.cpp new file mode 100644 index 00000000000..103702a8d14 --- /dev/null +++ b/src/devices/machine/adc0844.cpp @@ -0,0 +1,208 @@ +// license: BSD-3-Clause +// copyright-holders: Dirk Best +/*************************************************************************** + + ADC0844/ADC0848 + + A/D Converter With Multiplexer Options + +***************************************************************************/ + +#include "emu.h" +#include "adc0844.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(ADC0844, adc0844_device, "adc0844", "ADC0844 A/D Converter") +DEFINE_DEVICE_TYPE(ADC0848, adc0848_device, "adc0848", "ADC0848 A/D Converter") + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// adc0844_device - constructor +//------------------------------------------------- + +adc0844_device::adc0844_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) : + device_t(mconfig, type, tag, owner, clock), + m_intr_cb(*this), + m_ch1_cb(*this), m_ch2_cb(*this), m_ch3_cb(*this), m_ch4_cb(*this), + m_conversion_timer(nullptr), + m_channel(0x0f), + m_result(0xff) +{ +} + +adc0844_device::adc0844_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : + adc0844_device(mconfig, ADC0844, tag, owner, clock) +{ +} + +//------------------------------------------------- +// adc0848_device - constructor +//------------------------------------------------- + +adc0848_device::adc0848_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : + adc0844_device(mconfig, ADC0848, tag, owner, clock), + m_ch5_cb(*this), m_ch6_cb(*this), m_ch7_cb(*this), m_ch8_cb(*this) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void adc0844_device::device_start() +{ + // resolve callbacks + m_intr_cb.resolve_safe(); + m_ch1_cb.resolve_safe(0xff); + m_ch2_cb.resolve_safe(0xff); + m_ch3_cb.resolve_safe(0xff); + m_ch4_cb.resolve_safe(0xff); + + // allocate timers + m_conversion_timer = timer_alloc(); + + // register for save states + save_item(NAME(m_channel)); + save_item(NAME(m_result)); +} + +void adc0848_device::device_start() +{ + adc0844_device::device_start(); + + // resolve callbacks + m_ch5_cb.resolve_safe(0xff); + m_ch6_cb.resolve_safe(0xff); + m_ch7_cb.resolve_safe(0xff); + m_ch8_cb.resolve_safe(0xff); +} + +//------------------------------------------------- +// clamp - restrict value to 0..255 +//------------------------------------------------- + +uint8_t adc0844_device::clamp(int value) +{ + if (value > 0xff) + return 0xff; + else if (value < 0) + return 0x00; + else + return value; +} + +//------------------------------------------------- +// device_timer - handler timer events +//------------------------------------------------- + +void adc0844_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + switch (m_channel) + { + // differential + case 0x00: + case 0x08: m_result = clamp(0xff - (m_ch2_cb(0) - m_ch1_cb(0))); break; + case 0x01: + case 0x09: m_result = clamp(0xff - (m_ch1_cb(0) - m_ch2_cb(0))); break; + case 0x02: + case 0x0a: m_result = clamp(0xff - (m_ch4_cb(0) - m_ch3_cb(0))); break; + case 0x03: + case 0x0b: m_result = clamp(0xff - (m_ch3_cb(0) - m_ch4_cb(0))); break; + // single-ended + case 0x04: m_result = m_ch1_cb(0); break; + case 0x05: m_result = m_ch2_cb(0); break; + case 0x06: m_result = m_ch3_cb(0); break; + case 0x07: m_result = m_ch4_cb(0); break; + // pseudo-differential + case 0x0c: m_result = clamp(0xff - (m_ch4_cb(0) - m_ch1_cb(0))); break; + case 0x0d: m_result = clamp(0xff - (m_ch4_cb(0) - m_ch2_cb(0))); break; + case 0x0e: m_result = clamp(0xff - (m_ch4_cb(0) - m_ch3_cb(0))); break; + // undefined + case 0x0f: m_result = 0x00; break; + } + + m_intr_cb(ASSERT_LINE); +} + +void adc0848_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + switch (m_channel) + { + // differential + case 0x00: + case 0x10: m_result = clamp(0xff - (m_ch2_cb(0) - m_ch1_cb(0))); break; + case 0x01: + case 0x11: m_result = clamp(0xff - (m_ch1_cb(0) - m_ch2_cb(0))); break; + case 0x02: + case 0x12: m_result = clamp(0xff - (m_ch4_cb(0) - m_ch3_cb(0))); break; + case 0x03: + case 0x13: m_result = clamp(0xff - (m_ch3_cb(0) - m_ch4_cb(0))); break; + case 0x04: + case 0x14: m_result = clamp(0xff - (m_ch6_cb(0) - m_ch5_cb(0))); break; + case 0x05: + case 0x15: m_result = clamp(0xff - (m_ch5_cb(0) - m_ch6_cb(0))); break; + case 0x06: + case 0x16: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch7_cb(0))); break; + case 0x07: + case 0x17: m_result = clamp(0xff - (m_ch7_cb(0) - m_ch8_cb(0))); break; + // single-ended + case 0x08: m_result = m_ch1_cb(0); break; + case 0x09: m_result = m_ch2_cb(0); break; + case 0x0a: m_result = m_ch3_cb(0); break; + case 0x0b: m_result = m_ch4_cb(0); break; + case 0x0c: m_result = m_ch5_cb(0); break; + case 0x0d: m_result = m_ch6_cb(0); break; + case 0x0e: m_result = m_ch7_cb(0); break; + case 0x0f: m_result = m_ch8_cb(0); break; + // pseudo-differential + case 0x18: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch1_cb(0))); break; + case 0x19: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch2_cb(0))); break; + case 0x1a: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch3_cb(0))); break; + case 0x1b: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch4_cb(0))); break; + case 0x1c: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch5_cb(0))); break; + case 0x1d: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch6_cb(0))); break; + case 0x1e: m_result = clamp(0xff - (m_ch8_cb(0) - m_ch7_cb(0))); break; + // undefined + case 0x1f: m_result = 0x00; break; + } + + m_intr_cb(ASSERT_LINE); +} + + +//************************************************************************** +// INTERFACE +//************************************************************************** + +READ8_MEMBER( adc0844_device::read ) +{ + m_intr_cb(CLEAR_LINE); + + return m_result; +} + +WRITE8_MEMBER( adc0844_device::write ) +{ + m_intr_cb(CLEAR_LINE); + + // set channel and start conversion + m_channel = data & 0x0f; + m_conversion_timer->adjust(attotime::from_usec(40)); +} + +WRITE8_MEMBER( adc0848_device::write ) +{ + m_intr_cb(CLEAR_LINE); + + // set channel and start conversion + m_channel = data & 0x1f; + m_conversion_timer->adjust(attotime::from_usec(40)); +} |