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(MESS) isa_sblaster: improved MIDI throttling (nw)

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This commit is contained in:
R. Belmont 2013-02-01 01:50:05 +00:00
parent 3e4de53899
commit b1b07eb9f2
2 changed files with 31 additions and 7 deletions
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34
src/mess/machine/isa_sblaster.c
View File

@ -272,6 +272,7 @@ WRITE8_MEMBER( sb_device::dsp_reset_w )
m_tx_busy = false;
m_xmit_read = m_xmit_write = 0;
m_recv_read = m_recv_write = 0;
m_uart_xmitfull = false;
//printf("%02x\n",data);
}
@ -320,9 +321,9 @@ READ8_MEMBER(sb_device::dsp_rbuf_status_r)
// printf("Clear IRQ5\n");
irq_w(0, IRQ_DMA8); // reading this port ACKs the card's IRQ, 8-bit dma only?
// in UART MIDI mode, bit 7 indicates if a character is available
// in either SB-MIDI mode, bit 7 indicates if a character is available
// to read.
if (m_uart_midi)
if (m_uart_midi || m_onebyte_midi)
{
if (m_recv_read != m_recv_write)
{
@ -338,9 +339,22 @@ READ8_MEMBER(sb_device::dsp_rbuf_status_r)
READ8_MEMBER(sb_device::dsp_wbuf_status_r)
{
// printf("read Wbufstat @ %x\n", offset);
if(offset)
return 0xff;
// in either SB-MIDI mode, bit 7 indicates if there's space to write.
// set = buffer full
if (m_uart_midi || m_onebyte_midi)
{
if (m_uart_xmitfull)
{
return 0x80;
}
return 0x00;
}
return m_dsp.wbuf_status;
}
@ -1207,6 +1221,15 @@ void sb_device::device_reset()
m_dsp.dma_no_irq = false;
mixer_reset();
m_onebyte_midi = false;
m_uart_midi = false;
m_uart_irq = false;
m_mpu_midi = false;
m_tx_busy = false;
m_xmit_read = m_xmit_write = 0;
m_recv_read = m_recv_write = 0;
m_uart_xmitfull = false;
// MIDI is 31250 baud, 8-N-1
set_rcv_rate(31250);
set_tra_rate(31250);
@ -1546,15 +1569,16 @@ void sb16_device::rcv_complete() // Rx completed receiving byte
void sb_device::tra_complete() // Tx completed sending byte
{
// printf("Tx complete\n");
// printf("Tx complete\n");
// is there more waiting to send?
if (m_xmit_read != m_xmit_write)
if ((m_xmit_read != m_xmit_write) || (m_uart_xmitfull))
{
transmit_register_setup(m_xmitring[m_xmit_read++]);
if (m_xmit_read >= MIDI_RING_SIZE)
{
m_xmit_read = 0;
}
m_uart_xmitfull = false;
}
else
{
@ -1589,7 +1613,7 @@ void sb_device::xmit_char(UINT8 data)
if (m_xmit_write == m_xmit_read)
{
printf("Overflow xmitring!\n");
m_uart_xmitfull = true;
}
}
}

4
src/mess/machine/isa_sblaster.h
View File

@ -135,12 +135,12 @@ protected:
virtual void tra_callback(); // Tx send bit
void input_callback(UINT8 state) {}
static const int MIDI_RING_SIZE = 1024;
static const int MIDI_RING_SIZE = 2048;
struct sb8_dsp_state m_dsp;
UINT8 m_dack_out;
void xmit_char(UINT8 data);
bool m_onebyte_midi, m_uart_midi, m_uart_irq, m_mpu_midi;
bool m_onebyte_midi, m_uart_midi, m_uart_irq, m_mpu_midi, m_uart_xmitfull;
UINT8 m_recvring[MIDI_RING_SIZE];
UINT8 m_xmitring[MIDI_RING_SIZE];
int m_xmit_read, m_xmit_write;