diff options
Diffstat (limited to 'src/devices/bus/spc1000/vdp.c')
-rw-r--r-- | src/devices/bus/spc1000/vdp.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/devices/bus/spc1000/vdp.c b/src/devices/bus/spc1000/vdp.c new file mode 100644 index 00000000000..7824e9fccb4 --- /dev/null +++ b/src/devices/bus/spc1000/vdp.c @@ -0,0 +1,106 @@ +// license:BSD-3-Clause +// copyright-holders:Fabio Priuli +/*************************************************************************** + + SPC-1000 VDP expansion unit + +***************************************************************************/ + +#include "emu.h" +#include "vdp.h" + + +/*************************************************************************** + IMPLEMENTATION +***************************************************************************/ + +WRITE_LINE_MEMBER(spc1000_vdp_exp_device::vdp_interrupt) +{ + // nothing here? +} + +static MACHINE_CONFIG_FRAGMENT(scp1000_vdp) + + MCFG_DEVICE_ADD("tms", TMS9928A, XTAL_10_738635MHz / 2) // TODO: which clock? + MCFG_TMS9928A_VRAM_SIZE(0x4000) + MCFG_TMS9928A_OUT_INT_LINE_CB(WRITELINE(spc1000_vdp_exp_device, vdp_interrupt)) + MCFG_TMS9928A_SCREEN_ADD_NTSC("tms_screen") + MCFG_SCREEN_UPDATE_DEVICE("tms", tms9928a_device, screen_update) +MACHINE_CONFIG_END + +//------------------------------------------------- +// device_mconfig_additions +//------------------------------------------------- + +machine_config_constructor spc1000_vdp_exp_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( scp1000_vdp ); +} + + +//************************************************************************** +// GLOBAL VARIABLES +//************************************************************************** + +const device_type SPC1000_VDP_EXP = &device_creator<spc1000_vdp_exp_device>; + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// spc1000_vdp_exp_device - constructor +//------------------------------------------------- + +spc1000_vdp_exp_device::spc1000_vdp_exp_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, SPC1000_VDP_EXP, "SPC1000 VDP expansion", tag, owner, clock, "spc1000_vdp_exp", __FILE__), + device_spc1000_card_interface(mconfig, *this), + m_vdp(*this, "tms") +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void spc1000_vdp_exp_device::device_start() +{ +} + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void spc1000_vdp_exp_device::device_reset() +{ +} + +/*------------------------------------------------- + read +-------------------------------------------------*/ +READ8_MEMBER(spc1000_vdp_exp_device::read) +{ + if (!(offset & 0x800)) + return 0xff; + + if (offset & 1) + return m_vdp->register_read(space, offset); + else + return m_vdp->vram_read(space, offset); +} + +//------------------------------------------------- +// write +//------------------------------------------------- + +WRITE8_MEMBER(spc1000_vdp_exp_device::write) +{ + if (offset & 0x800) + { + if (offset & 1) + m_vdp->register_write(space, offset, data); + else + m_vdp->vram_write(space, offset, data); + } +} |