contur::Cpu Class Reference

Concrete CPU implementation. More...

#include <cpu.h>

Inheritance diagram for contur::Cpu:

Public Member Functions
	Cpu (IMemory &memory)
	Constructs a CPU connected to the given memory.
	~Cpu () override
	Destroys CPU.
	Cpu (const Cpu &)=delete
Cpu &	operator= (const Cpu &)=delete
	Cpu (Cpu &&) noexcept
	Move-constructs CPU state.
Cpu &	operator= (Cpu &&) noexcept
	Move-assigns CPU state.
Interrupt	step (RegisterFile &regs) override
	Performs a single fetch-decode-execute cycle.
void	reset () noexcept override
	Resets the CPU's internal state (flags, etc.).
RegisterValue	flags () const noexcept
	Returns the current comparison flags.
Public Member Functions inherited from contur::ICPU
virtual	~ICPU ()=default

Private Attributes
std::unique_ptr< Impl >	impl_

Additional Inherited Members
Protected Member Functions inherited from contur::ICPU
	ICPU ()=default
	ICPU (const ICPU &)=default
ICPU &	operator= (const ICPU &)=default
	ICPU (ICPU &&)=default
ICPU &	operator= (ICPU &&)=default

Detailed Description

Concrete CPU implementation.

The CPU performs the fetch-decode-execute cycle:

1. Fetch: read Block from memory at address pointed to by PC
2. Decode: interpret the Block's fields (opcode, register, operand, state)
3. Execute: perform the operation (ALU for arithmetic/logic, direct for control flow)

Instruction encoding in Block:

• code — the Instruction opcode
• reg — target (or source) register index
• operand — immediate value, memory address, or second register index
• state — addressing mode: 0 = immediate, 1 = register-register

Definition at line 29 of file cpu.h.

Constructor & Destructor Documentation

Cpu() [1/3]

contur::Cpu::Cpu ( IMemory & memory )

explicit

Constructs a CPU connected to the given memory.

Parameters

memory

Reference to the memory subsystem (must outlive the CPU).

Referenced by Cpu(), Cpu(), operator=(), and operator=().

~Cpu()

contur::Cpu::~Cpu ( )

override

Destroys CPU.

Cpu() [2/3]

contur::Cpu::Cpu ( const Cpu & )

delete

References Cpu().

Cpu() [3/3]

contur::Cpu::Cpu ( Cpu && )

noexcept

Move-constructs CPU state.

References Cpu().

Member Function Documentation

flags()

RegisterValue contur::Cpu::flags ( ) const

nodiscardnoexcept

Returns the current comparison flags.

Flags are set by the Compare instruction:

• Bit 0 (ZERO_FLAG): set if operands were equal
• Bit 1 (SIGN_FLAG): set if first operand was less than second

References flags().

Referenced by flags().

operator=() [1/2]

Cpu & contur::Cpu::operator= ( const Cpu & )

delete

References Cpu().

operator=() [2/2]

Cpu & contur::Cpu::operator= ( Cpu && )

noexcept

Move-assigns CPU state.

References Cpu().

reset()

void contur::Cpu::reset ( )

overridevirtualnoexcept

Resets the CPU's internal state (flags, etc.).

Implements contur::ICPU.

References reset().

Referenced by reset().

step()

Interrupt contur::Cpu::step ( RegisterFile & regs )

nodiscardoverridevirtual

Performs a single fetch-decode-execute cycle.

Reads the instruction at the address given by the Program Counter in regs, decodes it, executes it (updating regs and possibly memory), and advances the PC.

Parameters

regs	The register file for the currently running process.

Returns

An Interrupt code indicating the result:

• Interrupt::Ok — normal execution, continue
• Interrupt::Exit — process requested termination (Halt/Int Exit)
• Interrupt::DivByZero — division by zero fault
• Interrupt::SystemCall — software interrupt (syscall)
• Interrupt::DeviceIO — I/O interrupt
• Interrupt::Error — generic error (invalid instruction, etc.)

Implements contur::ICPU.

References step().

Referenced by step().

Member Data Documentation

impl_

std::unique_ptr<Impl> contur::Cpu::impl_

private

Definition at line 63 of file cpu.h.

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

• include/contur/cpu/cpu.h