diff options
Diffstat (limited to 'src/devices/machine/chessmachine.cpp')
-rw-r--r-- | src/devices/machine/chessmachine.cpp | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/src/devices/machine/chessmachine.cpp b/src/devices/machine/chessmachine.cpp index b260a089411..981904e1d84 100644 --- a/src/devices/machine/chessmachine.cpp +++ b/src/devices/machine/chessmachine.cpp @@ -26,6 +26,7 @@ probably went for this solution to get optimum possible speed for each module. TODO: - is interrupt handling correct? +- timer shouldn't be needed for disabling bootstrap, real ARM has already read the next opcode */ @@ -43,6 +44,8 @@ chessmachine_device::chessmachine_device(const machine_config &mconfig, const ch device_t(mconfig, CHESSMACHINE, tag, owner, clock), m_maincpu(*this, "maincpu"), m_bootstrap(*this, "bootstrap"), + m_ram(*this, "ram"), + m_disable_bootstrap(*this, "disable_bootstrap"), m_data_out(*this) { } @@ -57,8 +60,12 @@ void chessmachine_device::device_start() // resolve callbacks m_data_out.resolve_safe(); - // zerofill, register for savestates + // zerofill + m_bootstrap_enabled = false; m_latch[0] = m_latch[1] = 0; + + // register for savestates + save_item(NAME(m_bootstrap_enabled)); save_item(NAME(m_latch)); } @@ -96,11 +103,7 @@ void chessmachine_device::reset_w(int state) m_maincpu->set_input_line(INPUT_LINE_RESET, state ? ASSERT_LINE : CLEAR_LINE); if (state) - { - // send bootstrap - for (int i = 0; i < 0x80; i++) - m_maincpu->space(AS_PROGRAM).write_byte(i, m_bootstrap[i]); - } + m_bootstrap_enabled = true; } @@ -109,11 +112,26 @@ void chessmachine_device::reset_w(int state) // internal //------------------------------------------------- +u32 chessmachine_device::bootstrap_r(offs_t offset) +{ + return (m_bootstrap_enabled) ? m_bootstrap[offset] : m_ram[offset]; +} + +u32 chessmachine_device::disable_bootstrap_r() +{ + // disconnect bootstrap rom from the bus after next opcode + if (m_bootstrap_enabled && !m_disable_bootstrap->enabled() && !machine().side_effects_disabled()) + m_disable_bootstrap->adjust(m_maincpu->cycles_to_attotime(5)); + + return 0; +} + void chessmachine_device::main_map(address_map &map) { - map(0x00000000, 0x000fffff).ram(); + map(0x00000000, 0x000fffff).ram().share("ram"); + map(0x00000000, 0x0000007f).r(FUNC(chessmachine_device::bootstrap_r)); map(0x00400000, 0x00400000).mirror(0x003ffffc).rw(FUNC(chessmachine_device::internal_r), FUNC(chessmachine_device::internal_w)); - //map(0x01800000, 0x01800003).nopr(); // disconnect bootstrap? + map(0x01800000, 0x01800003).r(FUNC(chessmachine_device::disable_bootstrap_r)); } void chessmachine_device::device_add_mconfig(machine_config &config) @@ -121,6 +139,8 @@ void chessmachine_device::device_add_mconfig(machine_config &config) ARM(config, m_maincpu, DERIVED_CLOCK(1,1)); m_maincpu->set_addrmap(AS_PROGRAM, &chessmachine_device::main_map); m_maincpu->set_copro_type(arm_cpu_device::copro_type::VL86C020); + + TIMER(config, "disable_bootstrap").configure_generic(FUNC(chessmachine_device::disable_bootstrap)); } @@ -130,7 +150,7 @@ void chessmachine_device::device_add_mconfig(machine_config &config) //------------------------------------------------- ROM_START( chessmachine ) - ROM_REGION( 0x80, "bootstrap", 0 ) + ROM_REGION32_LE( 0x80, "bootstrap", 0 ) ROM_LOAD32_BYTE( "74s288.1", 0x00, 0x20, CRC(284114e2) SHA1(df4037536d505d7240bb1d70dc58f59a34ab77b4) ) ROM_LOAD32_BYTE( "74s288.2", 0x01, 0x20, CRC(9f239c75) SHA1(aafaf30dac90f36b01f9ee89903649fc4ea0480d) ) ROM_LOAD32_BYTE( "74s288.3", 0x02, 0x20, CRC(0455360b) SHA1(f1486142330f2c39a4d6c479646030d31443d1c8) ) |