VDP command engine by Alex Wulms. More...

#include <VDPCmdEngine.hh>

Public Member Functions
	VDPCmdEngine (VDP &vdp, CommandController &commandController)

void	reset (EmuTime::param time)
	Reinitialize Renderer state.

void	sync (EmuTime::param time)
	Synchronizes the command engine with the VDP.

void	sync2 (EmuTime::param time)

void	stealAccessSlot (EmuTime::param time)
	Steal a VRAM access slot from the CmdEngine.

byte	getStatus (EmuTime::param time)
	Gets the command engine status (part of S#2).

byte	readColor (EmuTime::param time)
	Use this method to transfer pixel(s) from VDP to CPU.

void	resetColor ()

unsigned	getBorderX (EmuTime::param time)
	Gets the X coordinate of a border detected by SRCH (intended behaviour, as documented in the V9938 technical data book).

void	setCmdReg (byte index, byte value, EmuTime::param time)
	Writes to a command register.

byte	peekCmdReg (byte index) const
	Read the content of a command register.

void	updateDisplayMode (DisplayMode mode, bool cmdBit, EmuTime::param time)
	Informs the command engine of a VDP display mode change.

bool	commandInProgress (EmuTime::param time)

auto	getLastCommand () const
	Get the register-values for the last executed (or still in progress) command.

auto	getInprogressPosition () const
	Get the (source and destination) X/Y coordinates of the currently executing command.

template<typename Archive >
void	serialize (Archive &ar, unsigned version)
	Interface for logical operations.

Static Public Attributes
static constexpr byte	MXD = 0x20

static constexpr byte	MXS = 0x10

static constexpr byte	DIY = 0x08

static constexpr byte	DIX = 0x04

static constexpr byte	EQ = 0x02

static constexpr byte	MAJ = 0x01

Detailed Description

VDP command engine by Alex Wulms.

Implements command execution unit of V9938/58.

Definition at line 23 of file VDPCmdEngine.hh.

Constructor & Destructor Documentation

◆ VDPCmdEngine()

openmsx::VDPCmdEngine::VDPCmdEngine	(	VDP &	vdp,
		CommandController &	commandController
	)

Definition at line 1762 of file VDPCmdEngine.cc.

Member Function Documentation

◆ commandInProgress()

bool openmsx::VDPCmdEngine::commandInProgress ( EmuTime::param time )

inline

Definition at line 129 of file VDPCmdEngine.hh.

References sync().

◆ getBorderX()

unsigned openmsx::VDPCmdEngine::getBorderX ( EmuTime::param time )

inline

Gets the X coordinate of a border detected by SRCH (intended behaviour, as documented in the V9938 technical data book).

However, real VDP simply returns the current value of the ASX 'temporary source X' counter, regardless of the command that is being executed or was executed most recently

Parameters

time	The moment in emulated time this get occurs.

Definition at line 101 of file VDPCmdEngine.hh.

References sync().

◆ getInprogressPosition()

auto openmsx::VDPCmdEngine::getInprogressPosition ( ) const

inline

Get the (source and destination) X/Y coordinates of the currently executing command.

For debugging purposes only.

Definition at line 144 of file VDPCmdEngine.hh.

◆ getLastCommand()

auto openmsx::VDPCmdEngine::getLastCommand ( ) const

inline

Get the register-values for the last executed (or still in progress) command.

For debugging purposes only.

Definition at line 136 of file VDPCmdEngine.hh.

◆ getStatus()

byte openmsx::VDPCmdEngine::getStatus ( EmuTime::param time )

inline

Gets the command engine status (part of S#2).

Bit 7 (TR) is set when the command engine is ready for a pixel transfer. Bit 4 (BD) is set when the boundary color is detected. Bit 0 (CE) is set when a command is in progress.

Definition at line 70 of file VDPCmdEngine.hh.

References sync().

◆ peekCmdReg()

byte openmsx::VDPCmdEngine::peekCmdReg ( byte index ) const

Read the content of a command register.

This method is meant to be used by the debugger, there is no strict guarantee that the returned value is the correct value at exactly this moment in time (IOW this method does not sync the complete CmdEngine)

Parameters

index The register [0..14] to read from.

Definition at line 1864 of file VDPCmdEngine.cc.

References UNREACHABLE.

◆ readColor()

byte openmsx::VDPCmdEngine::readColor ( EmuTime::param time )

inline

Use this method to transfer pixel(s) from VDP to CPU.

This method implements V9938 S#7.

Parameters

time	The moment in emulated time this read occurs.

Returns: Color value of the pixel.

Definition at line 82 of file VDPCmdEngine.hh.

References sync().

◆ reset()

void openmsx::VDPCmdEngine::reset ( EmuTime::param time )

Reinitialize Renderer state.

Parameters

time	The moment in time the reset occurs.

Definition at line 1785 of file VDPCmdEngine.cc.

References openmsx::VDP::getCmdBit(), openmsx::VDP::getDisplayMode(), setCmdReg(), and updateDisplayMode().

◆ resetColor()

void openmsx::VDPCmdEngine::resetColor ( )

inline

Definition at line 86 of file VDPCmdEngine.hh.

◆ serialize()

template<typename Archive >

void openmsx::VDPCmdEngine::serialize	(	Archive &	ar,
		unsigned	version
	)

Interface for logical operations.

Definition at line 2617 of file VDPCmdEngine.cc.

References openmsx::Clock< FREQ_NUM, FREQ_DENOM >::getTime().

◆ setCmdReg()

void openmsx::VDPCmdEngine::setCmdReg	(	byte	index,
		byte	value,
		EmuTime::param	time
	)

Writes to a command register.

Parameters

index	The register [0..14] to write to.
value	The new value for the specified register.
time	The moment in emulated time this write occurs.

Definition at line 1796 of file VDPCmdEngine.cc.

References openmsx::TclCallback::execute(), sync(), and UNREACHABLE.

Referenced by reset().

◆ stealAccessSlot()

void openmsx::VDPCmdEngine::stealAccessSlot ( EmuTime::param time )

inline

Steal a VRAM access slot from the CmdEngine.

Used when the CPU reads/writes VRAM.

Parameters

time	The moment in time the CPU read/write is performed.

Definition at line 56 of file VDPCmdEngine.hh.

References openmsx::VDPAccessSlots::D1.

Referenced by openmsx::VDPVRAM::cpuRead(), and openmsx::VDPVRAM::cpuWrite().

◆ sync()

void openmsx::VDPCmdEngine::sync ( EmuTime::param time )

inline

Synchronizes the command engine with the VDP.

Ideally this would be a private method, but the current design doesn't allow that.

Parameters

time	The moment in emulated time to sync to.

Definition at line 47 of file VDPCmdEngine.hh.

References sync2().

Referenced by commandInProgress(), openmsx::VDPVRAM::cpuRead(), openmsx::VDPVRAM::cpuWrite(), getBorderX(), getStatus(), readColor(), setCmdReg(), openmsx::VDPVRAM::sync(), openmsx::VDPVRAM::updateDisplayEnabled(), updateDisplayMode(), and openmsx::VDPVRAM::updateSpritesEnabled().

◆ sync2()

void openmsx::VDPCmdEngine::sync2 ( EmuTime::param time )

Definition at line 2018 of file VDPCmdEngine.cc.

References UNREACHABLE.

Referenced by sync().

◆ updateDisplayMode()

void openmsx::VDPCmdEngine::updateDisplayMode	(	DisplayMode	mode,
		bool	cmdBit,
		EmuTime::param	time
	)

Informs the command engine of a VDP display mode change.

Parameters

mode	The new display mode.
cmdBit	Are VDP commands allowed in non-bitmap mode.
time	The moment in emulated time this change occurs.

Definition at line 1889 of file VDPCmdEngine.cc.

References openmsx::DisplayMode::getBase(), openmsx::DisplayMode::GRAPHIC4, openmsx::DisplayMode::GRAPHIC5, openmsx::DisplayMode::GRAPHIC6, openmsx::DisplayMode::GRAPHIC7, and sync().

Referenced by reset(), and openmsx::VDPVRAM::updateDisplayMode().

Member Data Documentation

◆ DIX

constexpr byte openmsx::VDPCmdEngine::DIX = 0x04

staticconstexpr

Definition at line 30 of file VDPCmdEngine.hh.

Referenced by openmsx::ImGuiBitmapViewer::paint().

◆ DIY

constexpr byte openmsx::VDPCmdEngine::DIY = 0x08

staticconstexpr

Definition at line 29 of file VDPCmdEngine.hh.

Referenced by openmsx::ImGuiBitmapViewer::paint().

◆ EQ

constexpr byte openmsx::VDPCmdEngine::EQ = 0x02

staticconstexpr

Definition at line 31 of file VDPCmdEngine.hh.

Referenced by openmsx::ImGuiBitmapViewer::paint().

◆ MAJ

constexpr byte openmsx::VDPCmdEngine::MAJ = 0x01

staticconstexpr

Definition at line 32 of file VDPCmdEngine.hh.

Referenced by openmsx::ImGuiBitmapViewer::paint().

◆ MXD

constexpr byte openmsx::VDPCmdEngine::MXD = 0x20

staticconstexpr

Definition at line 27 of file VDPCmdEngine.hh.

◆ MXS

constexpr byte openmsx::VDPCmdEngine::MXS = 0x10

staticconstexpr

Definition at line 28 of file VDPCmdEngine.hh.

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ VDPCmdEngine()

Member Function Documentation

◆ commandInProgress()

◆ getBorderX()

◆ getInprogressPosition()

◆ getLastCommand()

◆ getStatus()

◆ peekCmdReg()

◆ readColor()

◆ reset()

◆ resetColor()

◆ serialize()

◆ setCmdReg()

◆ stealAccessSlot()

◆ sync()

◆ sync2()

◆ updateDisplayMode()

Member Data Documentation

◆ DIX

◆ DIY

◆ EQ

◆ MAJ

◆ MXD

◆ MXS