/*************************************************************************** National Semiconductor INS8154 N-Channel 128-by-8 Bit RAM Input/Output (RAM I/O) TODO: Strobed modes ***************************************************************************/ #include "emu.h" #include "ins8154.h" /*************************************************************************** CONSTANTS ***************************************************************************/ #define VERBOSE 1 /* Mode Definition Register */ enum { MDR_BASIC = 0x00, MDR_STROBED_INPUT = 0x20, MDR_STROBED_OUTPUT = 0x60, MDR_STROBED_OUTPUT_3STATE = 0xe0 }; //************************************************************************** // LIVE DEVICE //************************************************************************** // device type definition const device_type INS8154 = &device_creator; //------------------------------------------------- // ins8154_device - constructor //------------------------------------------------- ins8154_device::ins8154_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, INS8154, "INS8154", tag, owner, clock) { } //------------------------------------------------- // device_config_complete - perform any // operations now that the configuration is // complete //------------------------------------------------- void ins8154_device::device_config_complete() { // inherit a copy of the static data const ins8154_interface *intf = reinterpret_cast(static_config()); if (intf != NULL) { *static_cast(this) = *intf; } // or initialize to defaults if none provided else { memset(&m_in_a_cb, 0, sizeof(m_in_a_cb)); memset(&m_in_b_cb, 0, sizeof(m_in_b_cb)); memset(&m_out_a_cb, 0, sizeof(m_out_a_cb)); memset(&m_out_b_cb, 0, sizeof(m_out_b_cb)); memset(&m_out_irq_cb, 0, sizeof(m_out_irq_cb)); } } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void ins8154_device::device_start() { /* resolve callbacks */ m_in_a_func.resolve(m_in_a_cb, *this); m_out_a_func.resolve(m_out_a_cb, *this); m_in_b_func.resolve(m_in_b_cb, *this); m_out_b_func.resolve(m_out_b_cb, *this); m_out_irq_func.resolve(m_out_irq_cb, *this); /* register for state saving */ save_item(NAME(m_in_a)); save_item(NAME(m_in_b)); save_item(NAME(m_out_a)); save_item(NAME(m_out_b)); save_item(NAME(m_mdr)); save_item(NAME(m_odra)); save_item(NAME(m_odrb)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void ins8154_device::device_reset() { m_in_a = 0; m_in_b = 0; m_out_a = 0; m_out_b = 0; m_mdr = 0; m_odra = 0; m_odrb = 0; } READ8_MEMBER(ins8154_device::ins8154_r) { UINT8 val = 0xff; if (offset > 0x24) { if (VERBOSE) { logerror("%s: INS8154 '%s' Read from invalid offset %02x!\n", machine().describe_context(), tag(), offset); } return 0xff; } switch (offset) { case 0x20: if(!m_in_a_func.isnull()) { val = m_in_a_func(0); } m_in_a = val; break; case 0x21: if(!m_in_b_func.isnull()) { val = m_in_b_func(0); } m_in_b = val; break; default: if (offset < 0x08) { if(!m_in_a_func.isnull()) { val = (m_in_a_func(0) << (8 - offset)) & 0x80; } m_in_a = val; } else { if(!m_in_b_func.isnull()) { val = (m_in_b_func(0) << (8 - (offset >> 4))) & 0x80; } m_in_b = val; } break; } return val; } WRITE8_MEMBER(ins8154_device::ins8154_porta_w) { m_out_a = data; /* Test if any pins are set as outputs */ if (m_odra) { m_out_a_func(0, (data & m_odra) | (m_odra ^ 0xff)); } } WRITE8_MEMBER(ins8154_device::ins8154_portb_w) { m_out_b = data; /* Test if any pins are set as outputs */ if (m_odrb) { m_out_b_func(0, (data & m_odrb) | (m_odrb ^ 0xff)); } } WRITE8_MEMBER(ins8154_device::ins8154_w) { if (offset > 0x24) { if (VERBOSE) { logerror("%s: INS8154 '%s' Write %02x to invalid offset %02x!\n", machine().describe_context(), tag(), data, offset); } return; } switch (offset) { case 0x20: ins8154_porta_w(space, 0, data); break; case 0x21: ins8154_portb_w(space, 0, data); break; case 0x22: if (VERBOSE) { logerror("%s: INS8154 '%s' ODRA set to %02x\n", machine().describe_context(), tag(), data); } m_odra = data; break; case 0x23: if (VERBOSE) { logerror("%s: INS8154 '%s' ODRB set to %02x\n", machine().describe_context(), tag(), data); } m_odrb = data; break; case 0x24: if (VERBOSE) { logerror("%s: INS8154 '%s' MDR set to %02x\n", machine().describe_context(), tag(), data); } m_mdr = data; break; default: if (offset & 0x10) { /* Set bit */ if (offset < 0x08) { ins8154_porta_w(space, 0, m_out_a |= offset & 0x07); } else { ins8154_portb_w(space, 0, m_out_b |= (offset >> 4) & 0x07); } } else { /* Clear bit */ if (offset < 0x08) { ins8154_porta_w(space, 0, m_out_a & ~(offset & 0x07)); } else { ins8154_portb_w(space, 0, m_out_b & ~((offset >> 4) & 0x07)); } } break; } }