uint16_t v25_common_device::v25_read_word(unsigned a)
{
if (BIT(a, 0))
return (v25_read_byte(a) | (v25_read_byte(a + 1) << 8));
// not sure about this - manual says FFFFC-FFFFE are "reserved"
if (a == 0xffffe)
return (m_program->read_byte(a) | (m_data->read_byte(0x1ff) << 8));
else if ((a & 0xffe00) == m_IDB && (m_RAMEN || BIT(a, 8)))
return m_data->read_word(a & 0x1ff);
else
return m_program->read_word(a);
}
int v25_read_word(v25_state_t *nec_state, unsigned a)
{
if( a & 1 )
return (v25_read_byte(nec_state, a) | (v25_read_byte(nec_state, a + 1) << 8));
unsigned page = a >> 8;
unsigned offs = a & 0xff;
if(RAMEN && page == (nec_state->IDB << 4 | 0xE))
return nec_state->ram.w[offs/2];
if(page == (nec_state->IDB << 4 | 0xF))
return (read_sfr(nec_state, offs) | (read_sfr(nec_state, offs+1) << 8));
if(a == 0xFFFFE) /* not sure about this */
return (nec_state->program->read_byte(a) | (read_sfr(nec_state, 0xFF) << 8));
return nec_state->program->read_word(a);
}