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-rw-r--r--src/devices/video/sed1500.cpp116
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diff --git a/src/devices/video/sed1500.cpp b/src/devices/video/sed1500.cpp
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+// license:BSD-3-Clause
+// copyright-holders:hap
+/*
+
+Epson SED1500 series LCD Driver
+128 bytes internal RAM.
+
+SED1500: 8 commons, 42 segments
+SED1501: 10 commons, 40 segments
+SED1502: 16 commons, 34 segments
+SED1503: 8 commons, 42 segments, needs multiple of 2 chips to function
+
+The default input OSC frequency is 32768Hz, the frame output frequency is
+divided by 64 and by number of commons, eg. 64Hz on a SED1500.
+
+TODO:
+- bus mode (only mode 3 now)
+- EI pin (master/slave mode)
+- SYNC pin, used for frame synchronizing if multiple chips are used
+- SED1503 only has 8 COM pins, the extra 8 outputs are from the slave chip
+
+*/
+
+#include "emu.h"
+#include "sed1500.h"
+
+
+DEFINE_DEVICE_TYPE(SED1500, sed1500_device, "sed1500", "Epson SED1500 LCD Driver")
+DEFINE_DEVICE_TYPE(SED1501, sed1501_device, "sed1501", "Epson SED1501 LCD Driver")
+DEFINE_DEVICE_TYPE(SED1502, sed1502_device, "sed1502", "Epson SED1502 LCD Driver")
+DEFINE_DEVICE_TYPE(SED1503, sed1503_device, "sed1503", "Epson SED1503 LCD Driver")
+
+//-------------------------------------------------
+// constructor
+//-------------------------------------------------
+
+sed1500_device::sed1500_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock, u8 cmax, u8 smax) :
+ device_t(mconfig, type, tag, owner, clock),
+ m_cmax(cmax), m_smax(smax),
+ m_write_segs(*this)
+{ }
+
+sed1500_device::sed1500_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+ sed1500_device(mconfig, SED1500, tag, owner, clock, 8, 42)
+{ }
+
+sed1501_device::sed1501_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+ sed1500_device(mconfig, SED1501, tag, owner, clock, 10, 40)
+{ }
+
+sed1502_device::sed1502_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+ sed1500_device(mconfig, SED1502, tag, owner, clock, 16, 34)
+{ }
+
+sed1503_device::sed1503_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+ sed1500_device(mconfig, SED1503, tag, owner, clock, 8+8, 42)
+{ }
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void sed1500_device::device_start()
+{
+ // timer
+ m_lcd_timer = timer_alloc(FUNC(sed1500_device::update_segs), this);
+ attotime period = attotime::from_hz(clock() / 64);
+ m_lcd_timer->adjust(period, 0, period);
+
+ // zerofill
+ m_mode = 0;
+ m_cout = 0;
+ std::fill_n(m_ram, std::size(m_ram), 0);
+
+ // register for savestates
+ save_item(NAME(m_mode));
+ save_item(NAME(m_cout));
+ save_item(NAME(m_ram));
+}
+
+
+//-------------------------------------------------
+// handlers
+//-------------------------------------------------
+
+TIMER_CALLBACK_MEMBER(sed1500_device::update_segs)
+{
+ u64 data = 0;
+
+ for (int i = m_smax-1; i >= 0; i--)
+ data = data << 1 | BIT(m_ram[i | 0x40] << 8 | m_ram[i], m_cout);
+
+ // transfer segments to output
+ m_write_segs(m_cout, data);
+ m_cout = (m_cout + 1) % m_cmax;
+}
+
+void sed1500_device::write(offs_t offset, u8 data)
+{
+ offset &= 0x7f;
+ m_ram[offset] = data;
+
+ // bus mode command:
+ // 0 = 4-bit addr, 4-bit data, combined
+ // 1 = 7-bit addr, 4-bit data, separate
+ // 2 = 7-bit addr, 8-bit data, combined
+ // 3 = 7-bit addr, 8-bit data, separate
+ if ((offset & 0x3f) == 0x3f && ~data & 1)
+ m_mode = data >> 1 & 3;
+}
+
+u8 sed1500_device::read(offs_t offset)
+{
+ return m_ram[offset & 0x7f];
+}