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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();
};
}