mirror of
https://github.com/TomHarte/CLK.git
synced 2024-12-25 18:30:21 +00:00
132 lines
3.8 KiB
C++
132 lines
3.8 KiB
C++
//
|
|
// 9918.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 25/11/2017.
|
|
// Copyright 2017 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef TMS9918_hpp
|
|
#define TMS9918_hpp
|
|
|
|
#include "../../Outputs/CRT/CRT.hpp"
|
|
#include "../../ClockReceiver/ClockReceiver.hpp"
|
|
|
|
#include <cstdint>
|
|
|
|
namespace TI::TMS {
|
|
|
|
enum Personality {
|
|
TMS9918A, // includes the 9928 and 9929; set TV standard and output device as desired.
|
|
|
|
// Yamaha extensions.
|
|
V9938,
|
|
V9958,
|
|
|
|
// Sega extensions.
|
|
SMSVDP,
|
|
SMS2VDP,
|
|
GGVDP,
|
|
MDVDP,
|
|
};
|
|
|
|
enum class TVStandard {
|
|
/*! i.e. 50Hz output at around 312.5 lines/field */
|
|
PAL,
|
|
/*! i.e. 60Hz output at around 262.5 lines/field */
|
|
NTSC
|
|
};
|
|
|
|
}
|
|
|
|
#include "Implementation/9918Base.hpp"
|
|
|
|
namespace TI::TMS {
|
|
|
|
/*!
|
|
Provides emulation of the TMS9918a, TMS9928 and TMS9929. Likely in the future to be the
|
|
vessel for emulation of sufficiently close derivatives, such as the Master System VDP.
|
|
|
|
The TMS9918 and descendants are video display generators that own their own RAM, making it
|
|
accessible through an implicitly-timed register interface, and (depending on model) can generate
|
|
PAL and NTSC component and composite video.
|
|
|
|
These chips have only one non-on-demand interaction with the outside world: an interrupt line.
|
|
See get_time_until_interrupt and get_interrupt_line for asynchronous operation options.
|
|
*/
|
|
template <Personality personality> class TMS9918: private Base<personality> {
|
|
public:
|
|
/*! Constructs an instance of the VDP that behaves according to the templated personality. */
|
|
TMS9918();
|
|
|
|
/*! Sets the TV standard for this TMS, if that is hard-coded in hardware. */
|
|
void set_tv_standard(TVStandard standard);
|
|
|
|
/*! Sets the scan target this TMS will post content to. */
|
|
void set_scan_target(Outputs::Display::ScanTarget *);
|
|
|
|
/*! Gets the current scan status. */
|
|
Outputs::Display::ScanStatus get_scaled_scan_status() const;
|
|
|
|
/*! Sets the type of CRT display. */
|
|
void set_display_type(Outputs::Display::DisplayType);
|
|
|
|
/*! Gets the type of CRT display. */
|
|
Outputs::Display::DisplayType get_display_type() const;
|
|
|
|
/*!
|
|
Runs the VDP for the number of cycles indicate; the input clock rate is implicitly assumed.
|
|
|
|
For everything except the Mega Drive VDP:
|
|
* the input clock rate should be 3579545 Hz, the NTSC colour clock rate.
|
|
|
|
For the Mega Drive:
|
|
* the input clock rate should be around 7.6MHz; 15/7ths of the NTSC colour
|
|
clock rate for NTSC output and 12/7ths of the PAL colour clock rate for PAL output.
|
|
*/
|
|
void run_for(const HalfCycles cycles);
|
|
|
|
/*! Sets a register value. */
|
|
void write(int address, uint8_t value);
|
|
|
|
/*! Gets a register value. */
|
|
uint8_t read(int address);
|
|
|
|
/*! Gets the current scan line; provided by the Sega VDPs only. */
|
|
uint8_t get_current_line() const;
|
|
|
|
/*! Gets the current latched horizontal counter; provided by the Sega VDPs only. */
|
|
uint8_t get_latched_horizontal_counter() const;
|
|
|
|
/*! Latches the current horizontal counter. */
|
|
void latch_horizontal_counter();
|
|
|
|
/*!
|
|
Returns the amount of time until @c get_interrupt_line would next change if
|
|
there are no interceding calls to @c write or to @c read.
|
|
|
|
If get_interrupt_line is true now of if get_interrupt_line would
|
|
never return true, returns HalfCycles::max().
|
|
*/
|
|
HalfCycles next_sequence_point() const;
|
|
|
|
/*!
|
|
Returns the amount of time until the nominated line interrupt position is
|
|
reached on line @c line. If no line interrupt position is defined for
|
|
this VDP, returns the time until the 'beginning' of that line, whatever
|
|
that may mean.
|
|
|
|
@line is relative to the first pixel line of the display and may be negative.
|
|
*/
|
|
HalfCycles get_time_until_line(int line);
|
|
|
|
/*!
|
|
@returns @c true if the interrupt line is currently active; @c false otherwise.
|
|
*/
|
|
bool get_interrupt_line() const;
|
|
};
|
|
|
|
}
|
|
|
|
#endif /* TMS9918_hpp */
|