Z80TestHarness Class

Definition

Base class for a Z80 emulator test harness. Implement this class to use it with the test suites.

public abstract class Z80TestHarness

Constructors

Name	Description
Z80TestHarness()

Properties

Name	Description
Cycles	Gets the recorded CPU cycles. Only available when RecordCycles is true.
FlagC	Gets or sets the carry flag, C.
FlagH	Gets or sets the half-carry flag, H.
FlagN	Gets or sets the add/subtract flag, N.
FlagPV	Gets or sets the parity/overflow flag, P/V.
FlagS	Gets or sets the sign flag, S.
FlagX	Gets or sets the undocumented X flag, bit 3 of the F register.
FlagY	Gets or sets the undocumented Y flag, bit 5 of the F register.
FlagZ	Gets or sets the zero flag, Z.
Halted	Gets or sets whether the CPU is in the halted state.
IFF1	Gets or sets the IFF1 interrupt flip-flop.
IFF2	Gets or sets the IFF2 interrupt flip-flop.
IM	Gets or sets the interrupt mode.
Interrupt	Gets or sets whether an interrupt is pending.
IOReader	Gets the IO reader implementation.
IOWriter	Gets the IO writer implementation.
MutableCycles	A mutable list of Cycles to update when RecordCycles is `true`, `null` otherwise.
RecordCycles	Gets or sets whether CPU cycles should be recorded.
RegisterA	Gets or sets the A register.
RegisterAF	Gets or sets the AF register pair.
RegisterB	Gets or sets the B register.
RegisterBC	Gets or sets the BC register pair.
RegisterC	Gets or sets the C register.
RegisterD	Gets or sets the D register.
RegisterDE	Gets or sets the DE register pair.
RegisterE	Gets or sets the E register.
RegisterF	Gets or sets the F register.
RegisterH	Gets or sets the H register.
RegisterHL	Gets or sets the HL register pair.
RegisterI	Gets or sets the I register.
RegisterIX	Gets or sets the IX register pair.
RegisterIXH	Gets or sets the IXH register.
RegisterIXL	Gets or sets the IXL register.
RegisterIY	Gets or sets the IY register pair.
RegisterIYH	Gets or sets the IYH register.
RegisterIYL	Gets or sets the IYL register.
RegisterL	Gets or sets the L register.
RegisterPC	Gets or sets the PC register.
RegisterQ	Gets or sets the internal Q register.
RegisterR	Gets or sets the R register.
RegisterSP	Gets or sets the SP register.
RegisterWZ	Gets or sets the internal WZ register, sometimes called MEMPTR.
RomArea	Gets or sets the ROM area in memory. Memory writes in this area by the emulator should be ignored.
ShadowRegisterAF	Gets or sets the AF' register pair.
ShadowRegisterBC	Gets or sets the BC' register pair.
ShadowRegisterDE	Gets or sets the DE' register pair.
ShadowRegisterHL	Gets or sets the HL' register pair.
TStates	Gets or sets the number of T-states (clock cycles) executed.

Methods

Name	Description
AssertEqual<T>(T, T, DefaultInterpolatedStringHandler)	Asserts that the actual value is equal to the expected value. If the values are not equal, an error is reported.
AssertFail(String)	Signals that a test has failed with the provided error message.
ClearMemory()	Clears memory.
CopyToMemory(UInt16, ReadOnlySpan<Byte>)	Copies a span of bytes into the memory starting at the specified address.
CopyToMemory(UInt16, IReadOnlyList<Byte>)	Copies a sequence of bytes into memory starting at the specified address.
CreateAssertionScope(String)	Creates an assertion scope that allows multiple AssertEqual<T>(T, T, DefaultInterpolatedStringHandler) assertions to be made with just one AssertFail(String).
ExecuteInstruction()	Executes a single instruction.
ExecuteInstruction(TextWriter)	Executes a single instruction with debug output.
OnRomAreaChanged()	Called when RomArea changes. Override to update your emulator with the ROM area.
ReadByteFromMemory(UInt16)	Reads a byte from memory.
ReadWordFromMemory(UInt16)	Reads a word in little endian format from memory.
Reset()	Resets the test harness state.
SetIO<TIO>(TIO)	Sets both the IO reader and writer to the same implementation.
WriteByteToMemory(UInt16, Byte)	Writes a byte to memory. Does not take RomArea into account as this is used by tests to setup memory.
WriteWordToMemory(UInt16, UInt16)	Writes a word in little endian format to memory. Does not take RomArea into account as this is used by tests to setup memory.

Last modified: 13 July 2025