mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-23 18:31:53 +00:00
87 lines
2.4 KiB
C++
87 lines
2.4 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 "Implementation/9918Base.hpp"
|
|
|
|
#include <cstdint>
|
|
|
|
namespace TI {
|
|
|
|
/*!
|
|
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.
|
|
*/
|
|
class TMS9918: public TMS9918Base {
|
|
public:
|
|
enum Personality {
|
|
TMS9918A, // includes the 9928 and 9929; set TV standard and output device as desired.
|
|
};
|
|
|
|
/*!
|
|
Constructs an instance of the drive controller that behaves according to personality @c p.
|
|
@param p The type of controller to emulate.
|
|
*/
|
|
TMS9918(Personality p);
|
|
|
|
enum TVStandard {
|
|
/*! i.e. 50Hz output at around 312.5 lines/field */
|
|
PAL,
|
|
/*! i.e. 60Hz output at around 262.5 lines/field */
|
|
NTSC
|
|
};
|
|
|
|
/*! Sets the TV standard for this TMS, if that is hard-coded in hardware. */
|
|
void set_tv_standard(TVStandard standard);
|
|
|
|
/*! Provides the CRT this TMS is connected to. */
|
|
Outputs::CRT::CRT *get_crt();
|
|
|
|
/*!
|
|
Runs the VCP for the number of cycles indicate; it is an implicit assumption of the code
|
|
that the input clock rate is 3579545 Hz, the NTSC colour clock rate.
|
|
*/
|
|
void run_for(const HalfCycles cycles);
|
|
|
|
/*! Sets a register value. */
|
|
void set_register(int address, uint8_t value);
|
|
|
|
/*! Gets a register value. */
|
|
uint8_t get_register(int address);
|
|
|
|
/*!
|
|
Returns the amount of time until get_interrupt_line would next return true if
|
|
there are no interceding calls to set_register or get_register.
|
|
|
|
If get_interrupt_line is true now, returns zero. If get_interrupt_line would
|
|
never return true, returns -1.
|
|
*/
|
|
HalfCycles get_time_until_interrupt();
|
|
|
|
/*!
|
|
@returns @c true if the interrupt line is currently active; @c false otherwise.
|
|
*/
|
|
bool get_interrupt_line();
|
|
};
|
|
|
|
};
|
|
|
|
#endif /* TMS9918_hpp */
|