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Starts to flesh out documentation.

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This commit is contained in:
Thomas Harte 2019-11-19 22:32:07 -05:00
parent 06edeea866
commit 7ff57f8cdf
2 changed files with 31 additions and 1 deletions
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2
Components/68901/MFP68901.cpp
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@ -277,7 +277,7 @@ void MFP68901::set_port_input(uint8_t input) {
}
uint8_t MFP68901::get_port_output() {
return 0xff;
return 0xff; // TODO.
}
void MFP68901::reevaluate_gpip_interrupts() {

30
Components/68901/MFP68901.hpp
View File

@ -21,28 +21,58 @@ class PortHandler {
// TODO: announce changes in output.
};
/*!
Models the Motorola 68901 Multi-Function Peripheral ('MFP').
*/
class MFP68901: public ClockingHint::Source {
public:
/// @returns the result of a read from @c address.
uint8_t read(int address);
/// Performs a write of @c value to @c address.
void write(int address, uint8_t value);
/// Advances the MFP by the supplied number of HalfCycles.
void run_for(HalfCycles);
/// @returns the number of cycles until the next possible sequence point — the next time
/// at which the interrupt line _might_ change. This object conforms to ClockingHint::Source
/// so that mechanism can also be used to reduce the quantity of calls into this class.
///
/// @discussion TODO, alas.
HalfCycles get_next_sequence_point();
/// Sets the current level of either of the timer event inputs — TAI and TBI in datasheet terms.
void set_timer_event_input(int channel, bool value);
/// Sets a port handler, a receiver that will be notified upon any change in GPIP output.
///
/// @discussion TODO.
void set_port_handler(PortHandler *);
/// Sets the current input GPIP values.
void set_port_input(uint8_t);
/// @returns the current GPIP output values.
///
/// @discussion TODO.
uint8_t get_port_output();
/// @returns @c true if the interrupt output is currently active; @c false otherwise.s
bool get_interrupt_line();
static const int NoAcknowledgement = 0x100;
/// Communicates an interrupt acknowledge cycle.
///
/// @returns the vector placed on the bus if any; @c NoAcknowledgement if nothing is loaded.
int acknowledge_interrupt();
struct InterruptDelegate {
/// Informs the delegate of a change in the interrupt line of the nominated MFP.
virtual void mfp68901_did_change_interrupt_status(MFP68901 *) = 0;
};
/// Sets a delegate that will be notified upon any change in the interrupt line.
void set_interrupt_delegate(InterruptDelegate *delegate);
// ClockingHint::Source.