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Attempts to wire ACIA interrupt signals into the MFP.

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This commit is contained in:
Thomas Harte 2019-10-21 23:02:30 -04:00
parent 7cb82fccc0
commit e30ba58e0d
3 changed files with 84 additions and 27 deletions
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50
Components/68901/MFP68901.cpp
View File

@ -9,7 +9,7 @@
#include "MFP68901.hpp"
#define LOG_PREFIX "[MFP] "
#define NDEBUG
//#define NDEBUG
#include "../../Outputs/Log.hpp"
using namespace Motorola::MFP68901;
@ -17,9 +17,15 @@ using namespace Motorola::MFP68901;
uint8_t MFP68901::read(int address) {
address &= 0x1f;
switch(address) {
case 0x00: LOG("Read: general purpose IO"); break;
case 0x01: LOG("Read: active edge"); break;
case 0x02: LOG("Read: data direction"); break;
case 0x00:
LOG("Read: general purpose IO " << PADHEX(2) << int(gpip_input_ | gpip_direction_));
return gpip_input_ | gpip_direction_;
case 0x01:
LOG("Read: active edge " << PADHEX(2) << int(gpip_active_edge_));
return gpip_active_edge_;
case 0x02:
LOG("Read: data direction " << PADHEX(2) << int(gpip_direction_));
return gpip_direction_;
case 0x03: LOG("Read: interrupt enable A"); break;
case 0x04: LOG("Read: interrupt enable B"); break;
case 0x05: LOG("Read: interrupt pending A"); break;
@ -46,9 +52,20 @@ uint8_t MFP68901::read(int address) {
void MFP68901::write(int address, uint8_t value) {
address &= 0x1f;
switch(address) {
case 0x00: LOG("Write: general purpose IO"); break;
case 0x01: LOG("Write: active edge"); break;
case 0x02: LOG("Write: data direction"); break;
case 0x00:
LOG("Write: general purpose IO " << PADHEX(2) << int(value));
gpip_output_ = value;
break;
case 0x01:
LOG("Write: active edge " << PADHEX(2) << int(value));
gpip_active_edge_ = value;
reevaluate_gpip_interrupts();
break;
case 0x02:
LOG("Write: data direction " << PADHEX(2) << int(value));
gpip_direction_ = value;
reevaluate_gpip_interrupts();
break;
case 0x03: LOG("Write: interrupt enable A"); break;
case 0x04: LOG("Write: interrupt enable B"); break;
case 0x05: LOG("Write: interrupt pending A"); break;
@ -173,3 +190,22 @@ void MFP68901::decrement_timer(int timer) {
// TODO: interrupt. Reload, possibly.
}
}
// MARK: - GPIP
void MFP68901::set_port_input(uint8_t input) {
gpip_input_ = input;
reevaluate_gpip_interrupts();
}
uint8_t MFP68901::get_port_output() {
return 0xff;
}
void MFP68901::reevaluate_gpip_interrupts() {
const uint8_t gpip_state = gpip_input_ ^ gpip_active_edge_;
// An interrupt is detected on any falling edge.
if((gpip_state ^ gpip_interrupt_state_) & gpip_interrupt_state_) {
LOG("Should post GPIP interrupt");
}
gpip_interrupt_state_ = gpip_state;
}

16
Components/68901/MFP68901.hpp
View File

@ -17,12 +17,7 @@ namespace MFP68901 {
class PortHandler {
public:
/*!
Requests the current input on the GPIP port.
*/
virtual uint8_t get_port_input() {
return 0xff;
}
// TODO: announce changes in output.
};
class MFP68901 {
@ -59,6 +54,15 @@ class MFP68901 {
} timers_[4];
HalfCycles cycles_left_;
// MARK: - GPIP
uint8_t gpip_input_ = 0;
uint8_t gpip_output_ = 0;
uint8_t gpip_active_edge_ = 0;
uint8_t gpip_direction_ = 0;
uint8_t gpip_interrupt_state_ = 0;
void reevaluate_gpip_interrupts();
};
}

45
Machines/AtariST/AtariST.cpp
View File

@ -214,7 +214,8 @@ class ConcreteMachine:
public Atari::ST::Machine,
public CPU::MC68000::BusHandler,
public CRTMachine::Machine,
public ClockingHint::Observer {
public ClockingHint::Observer,
public Motorola::ACIA::ACIA::InterruptDelegate {
public:
ConcreteMachine(const Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
mc68000_(*this),
@ -250,9 +251,14 @@ class ConcreteMachine:
memory_map_[0xff] = BusDevice::IO;
midi_acia_->set_interrupt_delegate(this);
keyboard_acia_->set_interrupt_delegate(this);
midi_acia_->set_clocking_hint_observer(this);
keyboard_acia_->set_clocking_hint_observer(this);
ikbd_.set_clocking_hint_observer(this);
set_gpip_input();
}
~ConcreteMachine() {
@ -408,19 +414,6 @@ class ConcreteMachine:
mfp_->write(int(address), cycle.value->halves.high);
}
}
/*
Atari ST GPIP bits:
GPIP 7: monochrome monitor detect
GPIP 6: RS-232 ring indicator
GPIP 5: FD/HD interrupt
GPIP 4: keyboard/MIDI interrupt
GPIP 3: unused
GPIP 2: RS-232 clear to send
GPIP 1: RS-232 carrier detect
GPIP 0: centronics busy
*/
break;
// Video controls.
@ -584,6 +577,7 @@ class ConcreteMachine:
};
BusDevice memory_map_[256];
// MARK: - Clocking Management.
bool may_defer_acias_ = true;
bool keyboard_needs_clock_ = false;
void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference clocking) final {
@ -594,6 +588,29 @@ class ConcreteMachine:
(midi_acia_.last_valid()->preferred_clocking() != ClockingHint::Preference::RealTime);
keyboard_needs_clock_ = ikbd_.preferred_clocking() != ClockingHint::Preference::None;
}
// MARK: - GPIP input.
void acia6850_did_change_interrupt_status(Motorola::ACIA::ACIA *acia) final {
set_gpip_input();
}
void set_gpip_input() {
/*
Atari ST GPIP bits:
GPIP 7: monochrome monitor detect
GPIP 6: RS-232 ring indicator
GPIP 5: FD/HD interrupt
GPIP 4: keyboard/MIDI interrupt
GPIP 3: unused
GPIP 2: RS-232 clear to send
GPIP 1: RS-232 carrier detect
GPIP 0: centronics busy
*/
mfp_->set_port_input(
0x80 |
((keyboard_acia_->get_interrupt_line() || midi_acia_->get_interrupt_line()) ? 0x10 : 0x00)
);
}
};
}