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eepromser: Serial EEPROMs don't actually have reset lines, so remove the device_reset handler that automatically switches back to STATE_IN_RESET at machine reset time

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This change might cause erratic behavior in some systems which should be deasserting CS by clearing their EEPROM latches on reset, but is more appropriate for some MCU-based systems which actually depend on CS being automatically asserted through pull-ups when their quasi-bidirectional ports are reset.
This commit is contained in:
AJR 2018-12-21 10:04:47 -05:00
parent cbf1582e4f
commit 0f3eb00085
3 changed files with 27 additions and 14 deletions
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11
src/devices/machine/eepromser.cpp
View File

@ -205,17 +205,6 @@ void eeprom_serial_base_device::device_start()
save_item(NAME(m_command));
save_item(NAME(m_address));
save_item(NAME(m_shift_register));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void eeprom_serial_base_device::device_reset()
{
// reset the base class
eeprom_base_device::device_reset();
// reset the state
set_state(STATE_IN_RESET);

1
src/devices/machine/eepromser.h
View File

@ -38,7 +38,6 @@ protected:
// device-level overrides
virtual void device_start() override;
virtual void device_reset() override;
// read interfaces differ between implementations

29
src/mame/drivers/cardinal.cpp
View File

@ -27,25 +27,39 @@ public:
cardinal_state(const machine_config &mconfig, device_type type, const char *tag)
: driver_device(mconfig, type, tag)
, m_eeprom(*this, "eeprom")
, m_address_select(false)
{
}
void cardinal(machine_config &config);
protected:
virtual void machine_start() override;
private:
u32 screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
u8 p1_r();
void p1_w(u8 data);
u8 vtlc_r();
void vtlc_w(u8 data);
void prog_map(address_map &map);
void ext_map(address_map &map);
required_device<eeprom_serial_93cxx_device> m_eeprom;
//required_device<crt9028_device> m_vtlc;
bool m_address_select;
};
void cardinal_state::machine_start()
{
save_item(NAME(m_address_select));
}
u32 cardinal_state::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
{
return 0;
@ -58,10 +72,21 @@ u8 cardinal_state::p1_r()
void cardinal_state::p1_w(u8 data)
{
// FIXME: this doesn't quite work
m_eeprom->cs_write(BIT(data, 0));
m_eeprom->di_write(BIT(data, 4));
m_eeprom->clk_write(BIT(data, 3));
m_address_select = BIT(data, 1);
}
u8 cardinal_state::vtlc_r()
{
return 0xff;
}
void cardinal_state::vtlc_w(u8 data)
{
logerror("%s: Writing %02X to CRT9028 %s register\n", machine().describe_context(), data, m_address_select ? "address" : "data");
}
void cardinal_state::prog_map(address_map &map)
@ -71,7 +96,7 @@ void cardinal_state::prog_map(address_map &map)
void cardinal_state::ext_map(address_map &map)
{
map(0xff00, 0xff00).nopr();
map(0xff00, 0xff00).mirror(0xff).rw(FUNC(cardinal_state::vtlc_r), FUNC(cardinal_state::vtlc_w));
}