Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-10-05 16:50:57 +03:00
Code Issues Actions 3 Packages Projects Releases Wiki Activity

i8275: Cleanup. (nw)

Browse Source
This commit is contained in:
Curt Coder 2014-04-30 13:47:46 +00:00
parent c587682c58
commit fb8592f3d0
1 changed files with 39 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
src/emu/video/i8275.c
View File

@ -115,6 +115,7 @@ i8275_device::i8275_device(const machine_config &mconfig, const char *tag, devic
m_lten(0),
m_scanline(0),
m_du(false),
m_dma_stop(false),
m_end_of_screen(false),
m_cursor_blink(0),
m_char_blink(0)
@ -206,7 +207,35 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
//if (LOG) logerror("I8275 '%s' y %u x %u VRTC 0\n", tag(), y, x);
m_write_vrtc(0);
}
else if (m_scanline == m_irq_scanline)
if (m_scanline < (m_vrtc_scanline - SCANLINES_PER_ROW))
{
if (lc == 0)
{
if (m_buffer_idx < CHARACTERS_PER_ROW)
{
m_status |= ST_DU;
m_du = true;
//if (LOG) logerror("I8275 '%s' y %u x %u DMA Underrun\n", tag(), y, x);
m_write_drq(0);
}
if (!m_du && !m_dma_stop)
{
// swap line buffers
m_buffer_dma = !m_buffer_dma;
m_buffer_idx = 0;
m_fifo_idx = 0;
// start DMA burst
m_drq_on_timer->adjust(clocks_to_attotime(DMA_BURST_SPACE));
}
}
}
if (m_scanline == m_irq_scanline)
{
if (m_status & ST_IE)
{
@ -215,7 +244,8 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
m_write_irq(ASSERT_LINE);
}
}
else if (m_scanline == m_vrtc_scanline)
if (m_scanline == m_vrtc_scanline)
{
//if (LOG) logerror("I8275 '%s' y %u x %u VRTC 1\n", tag(), y, x);
m_write_vrtc(1);
@ -237,27 +267,16 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
m_char_blink++;
m_char_blink &= 0x3f;
}
if (lc == 0)
if (m_scanline == m_vrtc_drq_scanline)
{
if ((m_scanline < m_vrtc_scanline - SCANLINES_PER_ROW) && (m_buffer_idx < CHARACTERS_PER_ROW) && !m_du)
{
m_status |= ST_DU;
m_du = true;
//if (LOG) logerror("I8275 '%s' y %u x %u DMA Underrun\n", tag(), y, x);
m_write_drq(0);
}
// swap line buffers
m_buffer_dma = !m_buffer_dma;
m_buffer_idx = 0;
m_fifo_idx = 0;
if ((!m_dma_stop && !m_du && (m_scanline < m_vrtc_scanline - SCANLINES_PER_ROW)) || (m_scanline == m_vrtc_drq_scanline))
{
// start DMA burst
m_drq_on_timer->adjust(clocks_to_attotime(DMA_BURST_SPACE));
}
// start DMA burst
m_drq_on_timer->adjust(clocks_to_attotime(DMA_BURST_SPACE));
}
if (m_scanline < m_vrtc_scanline)
@ -519,9 +538,7 @@ WRITE8_MEMBER( i8275_device::write )
WRITE8_MEMBER( i8275_device::dack_w )
{
//int y = m_screen->vpos();
//int x = m_screen->hpos();
//if (LOG) logerror("I8275 '%s' y %u x %u DACK %04x:%02x %u\n", tag(), y, x, offset, data, m_buffer_idx);
//if (LOG) logerror("I8275 '%s' y %u x %u DACK %04x:%02x %u\n", tag(), m_screen->vpos(), m_screen->hpos(), offset, data, m_buffer_idx);
m_write_drq(0);
@ -642,4 +659,6 @@ void i8275_device::recompute_parameters()
if (LOG) logerror("irq_y %u vrtc_y %u drq_y %u\n", m_irq_scanline, m_vrtc_scanline, m_vrtc_drq_scanline);
m_scanline_timer->adjust(m_screen->time_until_pos(0, 0), 0, m_screen->scan_period());
if (DOUBLE_SPACED_ROWS) fatalerror("Double spaced rows not supported!");
}