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Diffstat (limited to 'trunk/src/emu/machine/i8212.c')
-rw-r--r-- | trunk/src/emu/machine/i8212.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/trunk/src/emu/machine/i8212.c b/trunk/src/emu/machine/i8212.c new file mode 100644 index 00000000000..aff8d4bca8b --- /dev/null +++ b/trunk/src/emu/machine/i8212.c @@ -0,0 +1,165 @@ +/********************************************************************** + + Intel 8212 8-Bit Input/Output Port emulation + + Copyright MESS Team. + Visit http://mamedev.org for licensing and usage restrictions. + +**********************************************************************/ + +#include "emu.h" +#include "machine/devhelpr.h" +#include "i8212.h" + + + +//************************************************************************** +// MACROS / CONSTANTS +//************************************************************************** + +#define LOG 0 + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +// device type definition +const device_type I8212 = &device_creator<i8212_device>; + +//------------------------------------------------- +// i8212_device - constructor +//------------------------------------------------- + +i8212_device::i8212_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, I8212, "Intel 8212", tag, owner, clock), + m_md(I8212_MODE_INPUT), + m_stb(0) +{ + +} + + +//------------------------------------------------- +// device_config_complete - perform any +// operations now that the configuration is +// complete +//------------------------------------------------- + +void i8212_device::device_config_complete() +{ + // inherit a copy of the static data + const i8212_interface *intf = reinterpret_cast<const i8212_interface *>(static_config()); + if (intf != NULL) + *static_cast<i8212_interface *>(this) = *intf; + + // or initialize to defaults if none provided + else + { + memset(&m_out_int_cb, 0, sizeof(m_out_int_cb)); + memset(&m_in_di_cb, 0, sizeof(m_in_di_cb)); + memset(&m_out_do_cb, 0, sizeof(m_out_do_cb)); + } +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void i8212_device::device_start() +{ + // resolve callbacks + m_out_int_func.resolve(m_out_int_cb, *this); + m_in_di_func.resolve(m_in_di_cb, *this); + m_out_do_func.resolve(m_out_do_cb, *this); + + // register for state saving + save_item(NAME(m_md)); + save_item(NAME(m_stb)); + save_item(NAME(m_data)); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void i8212_device::device_reset() +{ + m_data = 0; + + if (m_md == I8212_MODE_OUTPUT) + { + // output data + m_out_do_func(0, m_data); + } +} + + +//------------------------------------------------- +// data_r - data latch read +//------------------------------------------------- + +READ8_MEMBER( i8212_device::data_r ) +{ + // clear interrupt line + m_out_int_func(CLEAR_LINE); + + if (LOG) logerror("I8212 '%s' INT: %u\n", tag(), CLEAR_LINE); + + return m_data; +} + + +//------------------------------------------------- +// data_w - data latch write +//------------------------------------------------- + +WRITE8_MEMBER( i8212_device::data_w ) +{ + // latch data + m_data = data; + + // output data + m_out_do_func(0, m_data); +} + + +//------------------------------------------------- +// md_w - mode write +//------------------------------------------------- + +WRITE_LINE_MEMBER( i8212_device::md_w ) +{ + if (LOG) logerror("I8212 '%s' Mode: %s\n", tag(), state ? "output" : "input"); + + m_md = state; +} + + +//------------------------------------------------- +// stb_w - data strobe write +//------------------------------------------------- + +WRITE_LINE_MEMBER( i8212_device::stb_w ) +{ + if (LOG) logerror("I8212 '%s' STB: %u\n", tag(), state); + + if (m_md == I8212_MODE_INPUT) + { + if (m_stb && !state) + { + // input data + m_data = m_in_di_func(0); + + // assert interrupt line + m_out_int_func(ASSERT_LINE); + + if (LOG) logerror("I8212 '%s' INT: %u\n", tag(), ASSERT_LINE); + } + } + + m_stb = state; +} |