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-rw-r--r--src/devices/video/hd61603.cpp101
1 files changed, 101 insertions, 0 deletions
diff --git a/src/devices/video/hd61603.cpp b/src/devices/video/hd61603.cpp
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+// license:BSD-3-Clause
+// copyright-holders:hap
+/*
+
+Hitachi HD61603 LCD Driver
+64 segment outputs, no duty cycle
+
+TODO:
+- OSC pin (input is resistor)
+- SB pin, halts internal clock
+- SYNC pin for chip cascading
+- RE pin, resets count
+- READY pin
+
+*/
+
+#include "emu.h"
+#include "video/hd61603.h"
+
+
+DEFINE_DEVICE_TYPE(HD61603, hd61603_device, "hd61603", "Hitachi HD61603 LCD Driver")
+
+//-------------------------------------------------
+// constructor
+//-------------------------------------------------
+
+hd61603_device::hd61603_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+ device_t(mconfig, HD61603, tag, owner, clock),
+ m_write_segs(*this)
+{ }
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void hd61603_device::device_start()
+{
+ // resolve callbacks
+ m_write_segs.resolve_safe();
+
+ // register for savestates
+ save_item(NAME(m_blank));
+ save_item(NAME(m_count));
+ save_item(NAME(m_data));
+ save_item(NAME(m_ram));
+}
+
+
+//-------------------------------------------------
+// handlers
+//-------------------------------------------------
+
+void hd61603_device::refresh_output()
+{
+ m_write_segs(0, m_blank ? 0 : m_ram);
+}
+
+void hd61603_device::data_w(u8 data)
+{
+ // 1-byte nop command
+ if (m_count == 0 && (data & 0xc) == 0xc)
+ return;
+
+ // each command is 4 writes
+ m_data = (m_data << 4) | (data & 0xf);
+ m_count = (m_count + 1) & 3;
+
+ if (m_count == 0)
+ {
+ switch (m_data >> 14 & 3)
+ {
+ // write byte
+ case 0:
+ {
+ u8 shift = (m_data >> 8 & 7) * 8;
+ u8 digit = bitswap<8>(m_data & 0xff, 0,1,2,3,4,5,6,7);
+ m_ram = (m_ram & ~(u64(0xff) << shift)) | u64(digit) << shift;
+ break;
+ }
+
+ // write bit
+ case 1:
+ {
+ u64 mask = u64(1) << (m_data & 0x3f);
+ m_ram = (m_ram & ~mask) | ((m_data & 0x2000) ? mask : 0);
+ break;
+ }
+
+ // set mode
+ case 2:
+ m_blank = BIT(m_data, 2);
+ break;
+
+ default:
+ break;
+ }
+
+ refresh_output();
+ }
+}