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z80sio: more corner cases (nw)

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This commit is contained in:
Vas Crabb 2017-10-31 10:18:39 +11:00
parent 91bc5e3bc9
commit 4beede1983
2 changed files with 39 additions and 24 deletions
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62
src/devices/machine/z80sio.cpp
View File

@ -1027,18 +1027,14 @@ void z80sio_channel::do_sioreg_wr0(uint8_t data)
case WR0_ERROR_RESET:
// error reset
LOGCMD("%s %s Ch:%c : Error Reset\n", FUNCNAME, tag(), 'A' + m_index);
if (m_rr1 & (RR1_CRC_FRAMING_ERROR | RR1_RX_OVERRUN_ERROR | RR1_PARITY_ERROR))
if ((WR1_RX_INT_FIRST == (m_wr1 & WR1_RX_INT_MODE_MASK)) && (m_rr1 & (RR1_CRC_FRAMING_ERROR | RR1_RX_OVERRUN_ERROR)))
{
// clearing framing and overrun errors advances the FIFO
m_rr1 &= ~(RR1_CRC_FRAMING_ERROR | RR1_RX_OVERRUN_ERROR | RR1_PARITY_ERROR);
advance_rx_fifo();
}
else
{
if (m_rx_fifo_depth && (WR1_RX_INT_FIRST == (m_wr1 & WR1_RX_INT_MODE_MASK)))
{
// shift the FIFO
m_rx_data_fifo >>= 8;
m_rx_error_fifo >>= 8;
// no more characters available in the FIFO?
if (!--m_rx_fifo_depth)
m_rr0 &= ~RR0_RX_CHAR_AVAILABLE;
}
m_rr1 &= ~(RR1_CRC_FRAMING_ERROR | RR1_RX_OVERRUN_ERROR | RR1_PARITY_ERROR);
}
break;
@ -1185,19 +1181,9 @@ uint8_t z80sio_channel::data_read()
{
uint8_t const data = uint8_t(m_rx_data_fifo & 0x000000ffU);
if (m_rx_fifo_depth && ((WR1_RX_INT_FIRST != (m_wr1 & WR1_RX_INT_MODE_MASK)) || !(m_rx_error_fifo & 0x000000ffU)))
{
// load error status from the FIFO
m_rr1 = (m_rr1 & ~RR1_CRC_FRAMING_ERROR) | uint8_t(m_rx_error_fifo & 0x000000ffU);
// shift the FIFO
m_rx_data_fifo >>= 8;
m_rx_error_fifo >>= 8;
// no more characters available in the FIFO?
if (!--m_rx_fifo_depth)
m_rr0 &= ~RR0_RX_CHAR_AVAILABLE;
}
// framing and overrun errors need to be cleared to advance the FIFO in interrupt-on-first mode
if ((WR1_RX_INT_FIRST != (m_wr1 & WR1_RX_INT_MODE_MASK)) || !(m_rr1 & (RR1_CRC_FRAMING_ERROR | RR1_RX_OVERRUN_ERROR)))
advance_rx_fifo();
LOG("Z80SIO \"%s\" Channel %c : Data Register Read '%02x'\n", owner()->tag(), 'A' + m_index, data);
@ -1243,6 +1229,32 @@ void z80sio_channel::receive_reset()
m_rx_bit = 0;
}
//-------------------------------------------------
// advance_rx_fifo - move to next received byte
//-------------------------------------------------
void z80sio_channel::advance_rx_fifo()
{
if (m_rx_fifo_depth)
{
if (--m_rx_fifo_depth)
{
// shift the FIFO
m_rx_data_fifo >>= 8;
m_rx_error_fifo >>= 8;
// load error status from the FIFO
m_rr1 = (m_rr1 & ~RR1_CRC_FRAMING_ERROR) | uint8_t(m_rx_error_fifo & 0x000000ffU);
}
else
{
// no more characters available in the FIFO
m_rr0 &= ~RR0_RX_CHAR_AVAILABLE;
}
}
}
//-------------------------------------------------
// receive_data - receive data word
//-------------------------------------------------
@ -1285,6 +1297,8 @@ void z80sio_channel::receive_data()
}
m_rr0 |= RR0_RX_CHAR_AVAILABLE;
if (!m_rx_fifo_depth)
m_rr1 |= uint8_t(rx_error);
// receive interrupt
switch (m_wr1 & WR1_RX_INT_MODE_MASK)

1
src/devices/machine/z80sio.h
View File

@ -161,6 +161,7 @@ public:
void receive_reset();
void receive_data();
void advance_rx_fifo();
DECLARE_WRITE_LINE_MEMBER( write_rx ) { m_rxd = state; }
DECLARE_WRITE_LINE_MEMBER( cts_w );