void mos6551_device::update_serial()
{
int brg = m_ctrl & CTRL_BRG_MASK;
if (brg == CTRL_BRG_16X_EXTCLK)
{
set_rcv_rate(m_ext_rxc / 16);
set_tra_rate(m_ext_rxc / 16);
}
else
{
int baud = clock() / brg_divider[brg] / 16;
set_tra_rate(baud);
if (m_ctrl & CTRL_RXC_BRG)
{
set_rcv_rate(baud);
}
else
{
set_rcv_rate(m_ext_rxc / 16);
}
int num_data_bits = 8;
int stop_bit_count = 1;
int parity_code = PARITY_NONE;
switch (m_ctrl & CTRL_WL_MASK)
{
case CTRL_WL_8: num_data_bits = 8; break;
case CTRL_WL_7: num_data_bits = 7; break;
case CTRL_WL_6: num_data_bits = 6; break;
case CTRL_WL_5: num_data_bits = 5; break;
}
set_data_frame(num_data_bits, stop_bit_count, parity_code, false);
}
if (m_cmd & CMD_DTR)
m_connection_state |= DTR;
else
m_connection_state &= ~DTR;
m_dtr_handler((m_connection_state & DTR) ? 0 : 1);
if ((m_cmd & CMD_TC_MASK) == CMD_TC_RTS_HI)
m_connection_state &= ~RTS;
else
m_connection_state |= RTS;
m_rts_handler((m_connection_state & RTS) ? 0 : 1);
serial_connection_out();
}
void i8251_device::device_reset()
{
LOG("I8251: Reset\n");
/* what is the default setup when the 8251 has been reset??? */
/* i8251 datasheet explains the state of tx pin at reset */
/* tx is set to 1 */
m_txd_handler(1);
/* assumption */
m_rts_handler(1);
m_dtr_handler(1);
transmit_register_reset();
receive_register_reset();
m_flags = 0;
/* expecting mode byte */
m_flags |= I8251_EXPECTING_MODE;
/* not expecting a sync byte */
m_flags &= ~I8251_EXPECTING_SYNC_BYTE;
/* no character to read by cpu */
/* transmitter is ready and is empty */
m_status = I8251_STATUS_TX_EMPTY | I8251_STATUS_TX_READY;
m_mode_byte = 0;
m_command = 0;
m_rx_data = 0;
m_tx_data = 0;
m_rxc_count = m_txc_count = 0;
m_br_factor = 1;
/* update tx empty pin output */
update_tx_empty();
/* update rx ready pin output */
update_rx_ready();
/* update tx ready pin output */
update_tx_ready();
}
