mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-02 16:04:59 +00:00
134 lines
3.7 KiB
C++
134 lines
3.7 KiB
C++
//
|
|
// DiskController.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 14/07/2016.
|
|
// Copyright 2016 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef Storage_Disk_Controller_hpp
|
|
#define Storage_Disk_Controller_hpp
|
|
|
|
#include "../Drive.hpp"
|
|
#include "../DPLL/DigitalPhaseLockedLoop.hpp"
|
|
#include "../Track/PCMSegment.hpp"
|
|
|
|
#include "../../../ClockReceiver/ClockReceiver.hpp"
|
|
#include "../../../ClockReceiver/ClockingHintSource.hpp"
|
|
|
|
namespace Storage {
|
|
namespace Disk {
|
|
|
|
/*!
|
|
Provides the shell for emulating a disk controller: something that is connected to a disk drive and uses a
|
|
phase locked loop ('PLL') to decode a bit stream from the surface of the disk.
|
|
|
|
Partly abstract; it is expected that subclasses will provide methods to deal with receiving a newly-recognised
|
|
bit from the PLL and with crossing the index hole.
|
|
|
|
TODO: communication of head size and permissible stepping extents, appropriate simulation of gain.
|
|
*/
|
|
class Controller:
|
|
public DigitalPhaseLockedLoop::Delegate,
|
|
public Drive::EventDelegate,
|
|
public ClockingHint::Source,
|
|
public ClockingHint::Observer {
|
|
protected:
|
|
/*!
|
|
Constructs a @c Controller that will be run at @c clock_rate.
|
|
*/
|
|
Controller(Cycles clock_rate);
|
|
|
|
/*!
|
|
Communicates to the PLL the expected length of a bit as a fraction of a second.
|
|
*/
|
|
void set_expected_bit_length(Time bit_length);
|
|
|
|
/*!
|
|
Advances the drive by @c number_of_cycles cycles.
|
|
*/
|
|
void run_for(const Cycles cycles);
|
|
|
|
/*!
|
|
Sets the current drive. This drive is the one the PLL listens to.
|
|
*/
|
|
void set_drive(std::shared_ptr<Drive> drive);
|
|
|
|
/*!
|
|
Should be implemented by subclasses; communicates each bit that the PLL recognises.
|
|
*/
|
|
virtual void process_input_bit(int value) = 0;
|
|
|
|
/*!
|
|
Should be implemented by subclasses; communicates that the index hole has been reached.
|
|
*/
|
|
virtual void process_index_hole() = 0;
|
|
|
|
/*!
|
|
Should be implemented by subclasses if they implement writing; communicates that
|
|
all bits supplied to write_bit have now been written.
|
|
*/
|
|
virtual void process_write_completed() override;
|
|
|
|
/*!
|
|
Puts the controller and the drive returned by get_drive() into write mode, supplying to
|
|
the drive the current bit length.
|
|
|
|
While the controller is in write mode it disconnects the PLL. So subclasses will not
|
|
receive any calls to @c process_input_bit.
|
|
|
|
@param clamp_to_index_hole If @c true then writing will automatically be truncated by
|
|
the index hole. Writing will continue over the index hole otherwise.
|
|
*/
|
|
void begin_writing(bool clamp_to_index_hole);
|
|
|
|
/*!
|
|
Puts the drive returned by get_drive() out of write mode, and marks the controller
|
|
as no longer being in write mode.
|
|
*/
|
|
void end_writing();
|
|
|
|
/*!
|
|
@returns @c true if the controller is in reading mode; @c false otherwise.
|
|
*/
|
|
bool is_reading();
|
|
|
|
/*!
|
|
Returns the connected drive or, if none is connected, an invented one. No guarantees are
|
|
made about the lifetime or the exclusivity of the invented drive.
|
|
*/
|
|
Drive &get_drive();
|
|
|
|
/*!
|
|
As per ClockingHint::Source.
|
|
*/
|
|
ClockingHint::Preference preferred_clocking() override;
|
|
|
|
private:
|
|
Time bit_length_;
|
|
int clock_rate_multiplier_ = 1;
|
|
int clock_rate_ = 1;
|
|
|
|
bool is_reading_ = true;
|
|
|
|
std::shared_ptr<DigitalPhaseLockedLoop> pll_;
|
|
std::shared_ptr<Drive> drive_;
|
|
|
|
std::shared_ptr<Drive> empty_drive_;
|
|
|
|
// ClockingHint::Observer.
|
|
void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference clocking) override;
|
|
|
|
// for Drive::EventDelegate
|
|
void process_event(const Track::Event &event) override;
|
|
void advance(const Cycles cycles) override ;
|
|
|
|
// to satisfy DigitalPhaseLockedLoop::Delegate
|
|
void digital_phase_locked_loop_output_bit(int value) override;
|
|
};
|
|
|
|
}
|
|
}
|
|
|
|
#endif /* DiskDrive_hpp */
|