Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-04-23 08:49:55 +03:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

quizpun2: better way for stalling maincpu for mcu comms

Browse Source
This commit is contained in:
hap 2024-10-27 00:46:34 +02:00
parent 8353b2bd93
commit 26fe79b027
1 changed files with 28 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
src/mame/misc/quizpun2.cpp
View File

@ -149,13 +149,13 @@ private:
tilemap_t *m_bg_tmap;
tilemap_t *m_fg_tmap;
uint8_t m_scroll;
uint8_t m_scroll = 0;
uint8_t m_mcu_data_port;
uint8_t m_mcu_control_port;
bool m_mcu_pending;
bool m_mcu_written;
bool m_mcu_repeat;
uint8_t m_mcu_data_port = 0;
uint8_t m_mcu_control_port = 0;
bool m_mcu_pending = false;
bool m_mcu_written = false;
bool m_mcu_repeat = false;
TILE_GET_INFO_MEMBER(get_bg_tile_info);
TILE_GET_INFO_MEMBER(get_fg_tile_info);
@ -287,8 +287,8 @@ void quizpun2_state::machine_start()
save_item(NAME(m_mcu_data_port));
save_item(NAME(m_mcu_control_port));
save_item(NAME(m_mcu_pending));
save_item(NAME(m_mcu_repeat));
save_item(NAME(m_mcu_written));
save_item(NAME(m_mcu_repeat));
}
void quizpun2_state::machine_reset()
@ -296,7 +296,7 @@ void quizpun2_state::machine_reset()
m_mainbank->set_entry(0);
// quizpun2 service mode needs this to fix a race condition since the MCU takes a while to start up
m_maincpu->set_input_line(INPUT_LINE_HALT, ASSERT_LINE);
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, ASSERT_LINE);
m_mcu_data_port = m_mcu_control_port = 0;
m_mcu_pending = m_mcu_written = m_mcu_repeat = false;
@ -313,7 +313,7 @@ void quizpun2_state::cop_g_w(uint8_t data)
if (BIT(m_mcu_control_port, 0) && !BIT(data, 0))
{
m_mcu_pending = false;
m_maincpu->set_input_line(INPUT_LINE_HALT, CLEAR_LINE);
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, CLEAR_LINE);
}
m_mcu_control_port = data;
@ -326,8 +326,7 @@ uint8_t quizpun2_state::cop_l_r()
void quizpun2_state::cop_l_w(uint8_t data)
{
if (m_mcu_repeat)
m_mcu_data_port = data;
m_mcu_data_port = data;
}
uint8_t quizpun2_state::cop_in_r()
@ -389,31 +388,19 @@ void quizpun2_state::quizpun2_cop_map(address_map &map)
uint8_t quizpun2_state::protection_r()
{
LOGMCU("%s: port A read %02x\n", machine().describe_context(), m_mcu_data_port);
/*
Upon reading this port the main CPU is stalled until the MCU provides the value to read
and explicitly un-stalls the z80. Is this possible under the current MAME architecture?
** ghastly hack **
The first read stalls the main CPU and triggers the MCU, it returns an incorrect value.
It also decrements the main CPU PC back to the start of the read instruction.
When the MCU un-stalls the Z80, the read happens again, returning the correct MCU-provided value this time
*/
if (m_mcu_repeat)
if (!machine().side_effects_disabled())
{
m_mcu_repeat = false;
}
else
{
m_mcu_pending = true;
m_mcu_written = false;
m_maincpu->set_input_line(INPUT_LINE_HALT, ASSERT_LINE);
m_maincpu->yield();
// Z80 is stalled until the MCU provides the value to read and un-stalls the Z80
if (!m_mcu_repeat)
{
LOGMCU("%s: port A read %02x\n", machine().describe_context(), m_mcu_data_port);
m_mcu_pending = true;
m_mcu_written = false;
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, ASSERT_LINE);
m_maincpu->defer_access();
}
m_maincpu->set_state_int(Z80_PC, m_maincpu->state_int(Z80_PC) - 2);
m_mcu_repeat = true;
m_mcu_repeat = !m_mcu_repeat;
}
return m_mcu_data_port;
@ -425,8 +412,7 @@ void quizpun2_state::protection_w(uint8_t data)
m_mcu_data_port = data;
m_mcu_pending = true;
m_mcu_written = true;
m_maincpu->set_input_line(INPUT_LINE_HALT, ASSERT_LINE);
m_maincpu->yield();
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, ASSERT_LINE);
}
/***************************************************************************
@ -454,10 +440,9 @@ uint8_t quizpun2_state::quizpun_68705_port_b_r()
// bit 3: 0 = pending
// bit 1: 0 = main CPU has written
// bit 0: 0 = main CPU is reading
uint8_t const ret =
0xf4 |
( m_mcu_pending ? 0 : (1 << 3)) |
( m_mcu_pending ? 0 : (1 << 3)) |
((m_mcu_pending && m_mcu_written) ? 0 : (1 << 1)) |
((m_mcu_pending && !m_mcu_written) ? 0 : (1 << 0));
@ -470,11 +455,10 @@ void quizpun2_state::quizpun_68705_port_b_w(uint8_t data)
LOGMCU("%s: port B write %02x\n", machine().describe_context(), data);
// bit 2: 0->1 run main CPU
if (!BIT(m_mcu_control_port, 2) && BIT(data, 2))
{
m_mcu_pending = false;
m_maincpu->set_input_line(INPUT_LINE_HALT, CLEAR_LINE);
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, CLEAR_LINE);
}
m_mcu_control_port = data;
}
@ -643,6 +627,8 @@ void quizpun2_state::quizpun2(machine_config &config)
cop.read_si().set("eeprom", FUNC(eeprom_serial_93cxx_device::do_read));
cop.write_so().set("eeprom", FUNC(eeprom_serial_93cxx_device::di_write));
cop.write_sk().set("eeprom", FUNC(eeprom_serial_93cxx_device::clk_write));
config.set_perfect_quantum("cop");
}
void quizpun2_state::quizpun(machine_config &config)
@ -656,6 +642,8 @@ void quizpun2_state::quizpun(machine_config &config)
mcu.porta_w().set(FUNC(quizpun2_state::quizpun_68705_port_a_w));
mcu.portb_w().set(FUNC(quizpun2_state::quizpun_68705_port_b_w));
mcu.portc_w().set(FUNC(quizpun2_state::quizpun_68705_port_c_w));
config.set_perfect_quantum("mcu");
}
/***************************************************************************