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-rw-r--r--src/mame/machine/k007452.cpp101
1 files changed, 101 insertions, 0 deletions
diff --git a/src/mame/machine/k007452.cpp b/src/mame/machine/k007452.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Sean Gonsalves
+/***************************************************************************
+
+ Konami 007452 multiplier/divider
+
+***************************************************************************/
+
+#include "emu.h"
+#include "k007452.h"
+
+//**************************************************************************
+// CONSTANTS
+//**************************************************************************
+
+// device type definition
+DEFINE_DEVICE_TYPE(KONAMI_007452_MATH, k007452_device, "konami_007452", "Konami 007452 math chip")
+
+//-------------------------------------------------
+// k007452_device - constructor
+//-------------------------------------------------
+
+k007452_device::k007452_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
+ : device_t(mconfig, KONAMI_007452_MATH, tag, owner, clock)
+{
+}
+
+
+//-------------------------------------------------
+// read - read the registers
+//-------------------------------------------------
+
+uint8_t k007452_device::read(offs_t offset)
+{
+ switch (offset & 7)
+ {
+ case 0: return m_multiply_result & 0xff;
+ case 1: return (m_multiply_result >> 8) & 0xff;
+ case 2: return m_divide_remainder & 0xff;
+ case 3: return (m_divide_remainder >> 8) & 0xff;
+ case 4: return m_divide_quotient & 0xff;
+ case 5: return (m_divide_quotient >> 8) & 0xff;
+ default: return 0;
+ }
+}
+
+
+//-------------------------------------------------
+// write - write to the registers
+//-------------------------------------------------
+
+void k007452_device::write(offs_t offset, u8 data)
+{
+ if (offset < 6) m_math_regs[offset] = data;
+
+ if (offset == 1)
+ {
+ // Starts multiplication process
+ m_multiply_result = m_math_regs[0] * m_math_regs[1];
+ }
+ else if (offset == 5)
+ {
+ // Starts division process
+ u16 dividend = (m_math_regs[4]<<8) + m_math_regs[5];
+ u16 divisor = (m_math_regs[2]<<8) + m_math_regs[3];
+ if (!divisor) {
+ m_divide_quotient = 0xffff;
+ m_divide_remainder = 0x0000;
+ } else {
+ m_divide_quotient = dividend / divisor;
+ m_divide_remainder = dividend % divisor;
+ }
+ }
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void k007452_device::device_start()
+{
+ save_item(NAME(m_math_regs));
+ save_item(NAME(m_multiply_result));
+ save_item(NAME(m_divide_quotient));
+ save_item(NAME(m_divide_remainder));
+}
+
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void k007452_device::device_reset()
+{
+ std::fill(std::begin(m_math_regs), std::end(m_math_regs), 0);
+ m_multiply_result = 0;
+ m_divide_quotient = 0;
+ m_divide_remainder = 0;
+}
+