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svi318: simplify memory accesses

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This commit is contained in:
Dirk Best 2016-03-23 04:37:34 +01:00
parent 93e5a03b89
commit 6faedeb6bc
1 changed files with 24 additions and 50 deletions
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74
src/mame/drivers/svi318.cpp
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@ -32,6 +32,13 @@
#define IS_SVI328 (m_ram->size() == 64 * 1024)
#define CCS1 (m_cart == 0 && offset < 0x4000)
#define CCS2 (m_cart == 0 && offset >= 0x4000 && offset < 0x8000)
#define CCS3 (m_cart == 0 && m_rom2 == 0 && offset >= 0x8000 && offset < 0xc000)
#define CCS4 (m_cart == 0 && m_rom3 == 0 && offset >= 0xc000)
#define ROMCS (m_romdis == 1 && offset < 0x8000)
#define RAMCS (m_ramdis == 1 && offset >= 0x8000)
//**************************************************************************
// TYPE DEFINITIONS
@ -64,10 +71,8 @@ public:
DECLARE_WRITE8_MEMBER( bank_w );
DECLARE_WRITE_LINE_MEMBER( intvdp_w );
READ8_MEMBER( page1_r );
WRITE8_MEMBER( page1_w );
READ8_MEMBER( page2_r );
WRITE8_MEMBER( page2_w );
READ8_MEMBER( mreq_r );
WRITE8_MEMBER( mreq_w );
// from expander bus
DECLARE_WRITE_LINE_MEMBER( intexp_w );
@ -110,8 +115,7 @@ private:
static ADDRESS_MAP_START( svi3x8_mem, AS_PROGRAM, 8, svi3x8_state )
ADDRESS_MAP_UNMAP_HIGH
AM_RANGE(0x0000, 0x7fff) AM_READWRITE(page1_r, page1_w)
AM_RANGE(0x8000, 0xffff) AM_READWRITE(page2_r, page2_w)
AM_RANGE(0x0000, 0xffff) AM_READWRITE(mreq_r, mreq_w)
ADDRESS_MAP_END
static ADDRESS_MAP_START( svi3x8_io, AS_IO, 8, svi3x8_state )
@ -326,71 +330,41 @@ void svi3x8_state::machine_reset()
m_ramdis = 1;
m_cart = 1;
m_bk21 = 1;
m_rom2 = 1;
m_rom3 = 1;
m_keyboard_row = 0;
}
READ8_MEMBER( svi3x8_state::page1_r)
READ8_MEMBER( svi3x8_state::mreq_r )
{
// cartridge /CCS1 and /CCS2
if (m_cart == 0)
if (CCS1 || CCS2 || CCS3 || CCS4)
return m_cart_rom->read_rom(space, offset);
UINT8 data = m_expander->mreq_r(space, offset);
if (m_romdis == 1)
if (ROMCS)
data = m_basic->u8(offset);
if (m_bk21 == 0 && IS_SVI328)
if (m_bk21 == 0 && IS_SVI328 && offset < 0x8000)
data = m_ram->read(offset);
if (RAMCS && (IS_SVI328 || offset >= 0xc000))
data = m_ram->read(IS_SVI328 ? offset : offset - 0xc000);
return data;
}
WRITE8_MEMBER( svi3x8_state::page1_w)
WRITE8_MEMBER( svi3x8_state::mreq_w )
{
if (m_cart == 0)
if (CCS1 || CCS2 || CCS3 || CCS4)
return;
m_expander->mreq_w(space, offset, data);
if (m_bk21 == 0 && IS_SVI328)
if (m_bk21 == 0 && IS_SVI328 && offset < 0x8000)
m_ram->write(offset, data);
}
READ8_MEMBER( svi3x8_state::page2_r)
{
offset += 0x8000;
// cartridge /CCS3
if (m_cart == 0 && m_rom2 == 0 && offset < 0xc000)
return m_cart_rom->read_rom(space, offset);
// cartridge /CCS4
if (m_cart == 0 && m_rom3 == 0 && offset >= 0xc000)
return m_cart_rom->read_rom(space, offset);
UINT8 data = m_expander->mreq_r(space, offset);
if (m_ramdis == 1 && (offset >= 0x4000 || IS_SVI328))
return m_ram->read(IS_SVI328 ? offset : offset - 0xc000);
return data;
}
WRITE8_MEMBER( svi3x8_state::page2_w )
{
offset += 0x8000;
// cartridge /CCS3
if (m_cart == 0 && m_rom2 == 0 && offset < 0xc000)
return;
// cartridge /CCS4
if (m_cart == 0 && m_rom3 == 0 && offset >= 0xc000)
return;
m_expander->mreq_w(space, offset, data);
if (m_ramdis == 1 && (offset >= 0x4000 || IS_SVI328))
if (RAMCS && (IS_SVI328 || offset >= 0xc000))
m_ram->write(IS_SVI328 ? offset : offset - 0xc000, data);
}