openMSX
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openmsx::VDPCmdEngine Class Reference

VDP command engine by Alex Wulms. More...

#include <VDPCmdEngine.hh>

Public Member Functions

 VDPCmdEngine (VDP &vdp, CommandController &commandController)
 
void reset (EmuTime::param time)
 Reinitialise Renderer state. More...
 
void sync (EmuTime::param time)
 Synchronises the command engine with the VDP. More...
 
void sync2 (EmuTime::param time)
 
void stealAccessSlot (EmuTime::param time)
 Steal a VRAM access slot from the CmdEngine. More...
 
byte getStatus (EmuTime::param time)
 Gets the command engine status (part of S#2). More...
 
byte readColor (EmuTime::param time)
 Use this method to transfer pixel(s) from VDP to CPU. More...
 
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). More...
 
void setCmdReg (byte index, byte value, EmuTime::param time)
 Writes to a command register. More...
 
byte peekCmdReg (byte index)
 Read the content of a command register. More...
 
void updateDisplayMode (DisplayMode mode, bool cmdBit, EmuTime::param time)
 Informs the command engine of a VDP display mode change. More...
 
template<typename Archive >
void serialize (Archive &ar, unsigned version)
 Interface for logical operations. More...
 

Detailed Description

VDP command engine by Alex Wulms.

Implements command execution unit of V9938/58.

Definition at line 21 of file VDPCmdEngine.hh.

Constructor & Destructor Documentation

◆ VDPCmdEngine()

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

Definition at line 1732 of file VDPCmdEngine.cc.

Member Function Documentation

◆ 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
timeThe moment in emulated time this get occurs.

Definition at line 89 of file VDPCmdEngine.hh.

References openmsx::VDPAccessSlots::DELTA_0, openmsx::EmuTime, openmsx::VDP::getAccessSlot(), openmsx::VDP::getAccessSlotCalculator(), peekCmdReg(), serialize(), openmsx::SERIALIZE_CLASS_VERSION(), setCmdReg(), sync(), and updateDisplayMode().

◆ 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 58 of file VDPCmdEngine.hh.

References sync().

◆ peekCmdReg()

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

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
indexThe register [0..14] to read from.

Definition at line 1836 of file VDPCmdEngine.cc.

References UNREACHABLE.

Referenced by getBorderX().

◆ 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
timeThe moment in emulated time this read occurs.
Returns
Color value of the pixel.

Definition at line 70 of file VDPCmdEngine.hh.

References sync().

◆ reset()

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

Reinitialise Renderer state.

Parameters
timeThe moment in time the reset occurs.

Definition at line 1757 of file VDPCmdEngine.cc.

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

◆ resetColor()

void openmsx::VDPCmdEngine::resetColor ( )
inline

Definition at line 74 of file VDPCmdEngine.hh.

◆ serialize()

template<typename Archive >
void openmsx::VDPCmdEngine::serialize ( Archive &  ar,
unsigned  version 
)

Interface for logical operations.

Definition at line 2581 of file VDPCmdEngine.cc.

Referenced by getBorderX().

◆ setCmdReg()

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

Writes to a command register.

Parameters
indexThe register [0..14] to write to.
valueThe new value for the specified register.
timeThe moment in emulated time this write occurs.

Definition at line 1768 of file VDPCmdEngine.cc.

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

Referenced by getBorderX(), and 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
timeThe moment in time the CPU read/write is performed.

Definition at line 45 of file VDPCmdEngine.hh.

References openmsx::VDPAccessSlots::DELTA_1.

◆ sync()

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

Synchronises the command engine with the VDP.

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

Parameters
timeThe moment in emulated time to sync to.

Definition at line 36 of file VDPCmdEngine.hh.

References sync2().

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

◆ sync2()

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

◆ updateDisplayMode()

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

Informs the command engine of a VDP display mode change.

Parameters
modeThe new display mode.
cmdBitAre VDP commands allowed in non-bitmap mode.
timeThe moment in emulated time this change occurs.

Definition at line 1861 of file VDPCmdEngine.cc.

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

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


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