mame/src/emu/machine/tms6100.c

/**********************************************************************************************

     TMS6100 simulator

     Written for MAME by Couriersud

     Todo:
        - implement CS
        - implement 4 bit mode (mask programmed)
        - implement chip addressing (0-15 mask programmed)

     TMS6100:

                 +-----------------+
       VDD       |  1           28 |  NC
       NC        |  2           27 |  NC
       DATA/ADD1 |  3           26 |  NC
       DATA/ADD2 |  4           25 |  NC
       DATA/ADD4 |  5           24 |  NC
       DATA/ADD8 |  6           23 |  NC
       CLK       |  7           22 |  NC
       NC        |  8           21 |  NC
       NC        |  9           20 |  NC
       M0        | 10           19 |  NC
       M1        | 11           18 |  NC
       NC        | 12           17 |  NC
       /CS       | 13           16 |  NC
       VSS       | 14           15 |  NC
                 +-----------------+

    M58819 (from radarscope schematics):

                 +-----------------+
       AD0       |  1           40 |  AD1
       GND       |  2           39 |  AD2
       -5V       |  3           38 |  AD3
       A0        |  4           37 |  AD4
       NC        |  5           36 |  AD5
       NC        |  6           35 |  AD6
       A1        |  7           34 |  AD7
       A2        |  8           33 |  AD8
       A3        |  9           32 |  AD9
       CLK       | 10           31 |  AD10
       NC        | 11           30 |  AD11
       -5V       | 12           29 |  AD12
       C0        | 13           28 |  NC
       C1        | 14           27 |  NC
       NC        | 15           26 |  I7
       NC        | 16           25 |  NC
       +5V       | 17           24 |  I6
       I0        | 18           23 |  I5
       I1        | 19           22 |  I4
       I2        | 20           21 |  I3
                 +-----------------+

    The M58819 is used as an interface to external speech eproms.
    NC pins may have a function, although they are not connected in
    radarscope.

***********************************************************************************************/

#include "emu.h"
#include "tms6100.h"

#define VERBOSE     (0)

#if VERBOSE
#define LOG(x)      logerror x
#else
#define LOG(x)
#endif

#define TMS6100_READ_PENDING        0x01
#define TMS6100_NEXT_READ_IS_DUMMY  0x02


const device_type TMS6100 = &device_creator<tms6100_device>;

tms6100_device::tms6100_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source)
	: device_t(mconfig, type, name, tag, owner, clock, shortname, source)
{
}

tms6100_device::tms6100_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
	: device_t(mconfig, TMS6100, "TMS6100", tag, owner, clock, "tms6100", __FILE__)
{
}

const device_type M58819 = &device_creator<m58819_device>;

m58819_device::m58819_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
	: tms6100_device(mconfig, M58819, "M58819 Memory Controller", tag, owner, clock, "m58819", __FILE__)
{
}

//-------------------------------------------------
//  device_config_complete - perform any
//  operations now that the configuration is
//  complete
//-------------------------------------------------

void tms6100_device::device_config_complete()
{
}

//-------------------------------------------------
//  device_start - device-specific startup
//-------------------------------------------------

void tms6100_device::device_start()
{
	m_rom = *region();

	// save device variables
	save_item(NAME(m_addr_bits));
	save_item(NAME(m_address));
	save_item(NAME(m_address_latch));
	save_item(NAME(m_tms_clock));
	save_item(NAME(m_data));
	save_item(NAME(m_loadptr));
	save_item(NAME(m_m0));
	save_item(NAME(m_m1));
	save_item(NAME(m_state));

}

void m58819_device::device_start()
{
	//tms5110_set_variant(tms, TMS5110_IS_5100);
	tms6100_device::device_start();
}

//-------------------------------------------------
//  device_reset - device-specific reset
//-------------------------------------------------

void tms6100_device::device_reset()
{
	/* initialize the chip */
	m_addr_bits = 0;
	m_address = 0;
	m_address_latch = 0;
	m_loadptr = 0;
	m_m0 = 0;
	m_m1 = 0;
	m_state = 0;
	m_tms_clock = 0;
	m_data = 0;
}

WRITE_LINE_MEMBER(tms6100_device::tms6100_m0_w)
{
	if (state != m_m0)
		m_m0 = state;
}

WRITE_LINE_MEMBER(tms6100_device::tms6100_m1_w)
{
	if (state != m_m1)
		m_m1 = state;
}

WRITE_LINE_MEMBER(tms6100_device::tms6100_romclock_w)
{
	/* process on falling edge */
	if (m_tms_clock && !state)
	{
		switch ((m_m1<<1) | m_m0)
		{
		case 0x00:
			/* NOP in datasheet, not really ... */
			if (m_state & TMS6100_READ_PENDING)
			{
				if (m_state & TMS6100_NEXT_READ_IS_DUMMY)
				{
					m_address = (m_address_latch << 3);
					m_address_latch = 0;
					m_loadptr = 0;
					m_state &= ~TMS6100_NEXT_READ_IS_DUMMY;
					LOG(("loaded address %08x\n", m_address));
				}
				else
				{
					/* read bit at address */
					m_data = (m_rom[m_address >> 3] >> ((m_address & 0x07) ^ 0x07)) & 1;
					m_address++;
				}
				m_state &= ~TMS6100_READ_PENDING;
			}
			break;
		case 0x01:
			/* READ */
			m_state |= TMS6100_READ_PENDING;
			break;
		case 0x02:
			/* LOAD ADDRESS */
			m_state |= TMS6100_NEXT_READ_IS_DUMMY;
			m_address_latch |= (m_addr_bits << m_loadptr);
			LOG(("loaded address latch %08x\n", m_address_latch));
			m_loadptr += 4;
			break;
		case 0x03:
			/* READ AND BRANCH */
			if (m_state & TMS6100_NEXT_READ_IS_DUMMY)
			{
				m_state &= ~TMS6100_NEXT_READ_IS_DUMMY;  // clear - no dummy read according to datasheet
				LOG(("loaded address latch %08x\n", m_address_latch));
				m_address = m_rom[m_address_latch] | (m_rom[m_address_latch+1]<<8);
				m_address &= 0x3fff; // 14 bits
				LOG(("loaded indirect address %04x\n", m_address));
				m_address = (m_address << 3);
				m_address_latch = 0;
				m_loadptr = 0;
			}
			break;
		}
	}
	m_tms_clock = state;
}

WRITE8_MEMBER(tms6100_device::tms6100_addr_w)
{
	if (data != m_addr_bits)
		m_addr_bits = data;
}

READ_LINE_MEMBER(tms6100_device::tms6100_data_r)
{
	return m_data;
}