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mk68564: Emulate BRG; fix cut-and-paste error in pinout (nw)

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This commit is contained in:
AJR 2019-10-29 15:43:32 -04:00
parent cac86fb1b4
commit 736962d5e7
3 changed files with 67 additions and 15 deletions
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64
src/devices/machine/z80sio.cpp
View File

@ -78,6 +78,7 @@
#define LOG_SYNC (1U << 9)
#define LOG_BIT (1U << 10)
#define LOG_RTS (1U << 11)
#define LOG_BRG (1U << 12)
//#define VERBOSE (LOG_CMD | LOG_SETUP | LOG_SYNC | LOG_BIT | LOG_TX )
//#define LOG_OUTPUT_STREAM std::cout
@ -95,6 +96,7 @@
#define LOGDCD(...) LOGMASKED(LOG_DCD, __VA_ARGS__)
#define LOGSYNC(...) LOGMASKED(LOG_SYNC, __VA_ARGS__)
#define LOGBIT(...) LOGMASKED(LOG_BIT, __VA_ARGS__)
#define LOGBRG(...) LOGMASKED(LOG_BRG, __VA_ARGS__)
#ifdef _MSC_VER
#define FUNCNAME __func__
@ -979,6 +981,8 @@ mk68564_channel::mk68564_channel(const machine_config &mconfig, const char *tag,
, m_tx_auto_enable(false)
, m_brg_tc(0)
, m_brg_control(0)
, m_brg_state(false)
, m_brg_timer(nullptr)
{
}
@ -1055,9 +1059,12 @@ void mk68564_channel::device_start()
{
z80sio_channel::device_start();
m_brg_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(mk68564_channel::brg_timeout), this));
save_item(NAME(m_tx_auto_enable));
save_item(NAME(m_brg_tc));
save_item(NAME(m_brg_control));
save_item(NAME(m_brg_state));
}
@ -1117,6 +1124,8 @@ void mk68564_channel::device_reset()
m_tx_auto_enable = false;
m_brg_tc = 0;
m_brg_control = 0;
m_brg_state = false;
m_brg_timer->adjust(attotime::never);
}
bool z80sio_channel::is_tx_idle() const
@ -2758,7 +2767,6 @@ uint8_t mk68564_channel::tcreg_r()
//-------------------------------------------------
void mk68564_channel::tcreg_w(uint8_t data)
{
logerror("Time constant = %d\n", data);
m_brg_tc = data;
}
@ -2769,7 +2777,8 @@ void mk68564_channel::tcreg_w(uint8_t data)
//-------------------------------------------------
uint8_t mk68564_channel::brgctl_r()
{
return m_brg_control;
// unused bits are all zero
return m_brg_control & 0x0f;
}
@ -2779,15 +2788,20 @@ uint8_t mk68564_channel::brgctl_r()
//-------------------------------------------------
void mk68564_channel::brgctl_w(uint8_t data)
{
// TODO: actually emulate this
logerror("BRG %sabled, divide by %d, RxC %sternal, TxC %sternal\n",
BIT(data, 0) ? "en" : "dis",
BIT(data, 1) ? 64 : 4,
BIT(data, 2) ? "in" : "ex",
BIT(data, 3) ? "in" : "ex");
if (BIT(data, 0))
LOGBRG("%s: BRG enabled, divide by %d, RxC %sternal, TxC %sternal (TC = %d, %.1f Hz)\n",
machine().describe_context(),
BIT(data, 1) ? 64 : 4,
BIT(data, 2) ? "in" : "ex",
BIT(data, 3) ? "in" : "ex",
m_brg_tc,
clocks_to_attotime((m_brg_tc ? m_brg_tc : 256) * (BIT(data, 1) ? 64 : 4)).as_hz());
else
LOGBRG("%s: BRG disabled\n", machine().describe_context());
// unused bits are always zero
m_brg_control = data & 0x0f;
m_brg_state = false;
brg_update();
}
@ -2909,7 +2923,37 @@ void mk68564_device::write(offs_t offset, uint8_t data)
break;
default:
LOG("Write %02X to unused/read-only register %02X\n", data, offset & 0x1f);
logerror("Write %02X to unused/read-only register %02X\n", data, offset & 0x1f);
break;
}
}
//**************************************************************************
// MK68564 BAUD RATE GENERATOR
//**************************************************************************
void mk68564_device::set_xtal(uint32_t clock)
{
assert(!configured());
subdevice<mk68564_channel>(CHANA_TAG)->set_clock(clock);
subdevice<mk68564_channel>(CHANB_TAG)->set_clock(clock);
}
void mk68564_channel::brg_update()
{
if (BIT(m_brg_control, 2))
rxc_w(m_brg_state);
if (BIT(m_brg_control, 3))
txc_w(m_brg_state);
if (BIT(m_brg_control, 0))
m_brg_timer->adjust(clocks_to_attotime((m_brg_tc ? m_brg_tc : 256) * (BIT(m_brg_control, 1) ? 32 : 2)));
else
m_brg_timer->adjust(attotime::never);
}
TIMER_CALLBACK_MEMBER(mk68564_channel::brg_timeout)
{
m_brg_state = !m_brg_state;
brg_update();
}

14
src/devices/machine/z80sio.h
View File

@ -55,9 +55,9 @@
D5 3| |46 D4
D7 4| |45 D6
_INTR 5| |44 R/_W
IEO 6| |43 _IACK
IEI 7| |42 _DTACK
_M1 8| |41 _CS
CLK 6| |43 _IACK
XTAL1 7| |42 _DTACK
XTAL2 8| |41 _CS
_RESET 9| |40 _RxRDYB
_RxRDYA 10| |39 _TxRDYB
_TxRDYA 11| DIP48 |38 GND
@ -365,9 +365,14 @@ private:
uint8_t brgctl_r();
void brgctl_w(uint8_t data);
void brg_update();
TIMER_CALLBACK_MEMBER(brg_timeout);
bool m_tx_auto_enable;
uint8_t m_brg_tc;
uint8_t m_brg_control;
bool m_brg_state;
emu_timer *m_brg_timer;
};
@ -515,6 +520,9 @@ class mk68564_device : public i8274_new_device
public:
mk68564_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
void set_xtal(uint32_t clock);
void set_xtal(const XTAL &clock) { set_xtal(clock.value()); }
uint8_t read(offs_t offset);
void write(offs_t offset, uint8_t data);

4
src/mame/drivers/msbc1.cpp
View File

@ -102,8 +102,8 @@ void msbc1_state::msbc1(machine_config &config)
M68000(config, m_maincpu, 12.5_MHz_XTAL);
m_maincpu->set_addrmap(AS_PROGRAM, &msbc1_state::msbc1_mem);
MK68564(config, "sio1", 3.6864_MHz_XTAL);
MK68564(config, "sio2", 3.6864_MHz_XTAL);
MK68564(config, "sio1", 8_MHz_XTAL / 2).set_xtal(3.6864_MHz_XTAL);
MK68564(config, "sio2", 8_MHz_XTAL / 2).set_xtal(3.6864_MHz_XTAL);
}
/* ROM definition */