dolphin/Source/Core/Core/HW/SystemTimers.h

83 lines
2.1 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include "Common/CommonTypes.h"
namespace SystemTimers
{
/*
GameCube MHz
flipper <-> ARAM bus: 81 (DSP)
gekko <-> flipper bus: 162
flipper <-> 1T-SRAM bus: 324
gekko: 486
These contain some guesses:
Wii MHz
hollywood <-> GDDR3 RAM bus: ??? no idea really
broadway <-> hollywood bus: 243
hollywood <-> 1T-SRAM bus: 486
broadway: 729
*/
// Ratio of TB and Decrementer to clock cycles.
// TB clk is 1/4 of BUS clk. And it seems BUS clk is really 1/3 of CPU clk.
// So, ratio is 1 / (1/4 * 1/3 = 1/12) = 12.
// note: ZWW is ok and faster with TIMER_RATIO=8 though.
// !!! POSSIBLE STABLE PERF BOOST HACK THERE !!!
enum
{
TIMER_RATIO = 12
};
struct TimeBaseTick
{
constexpr TimeBaseTick() = default;
constexpr explicit TimeBaseTick(u64 tb_ticks) : cpu_ticks(tb_ticks * TIMER_RATIO) {}
constexpr operator u64() const { return cpu_ticks; }
u64 cpu_ticks = 0;
};
enum class Mode
{
GC,
Wii,
};
u32 GetTicksPerSecond();
void PreInit();
void Init();
void Shutdown();
void ChangePPCClock(Mode mode);
// Notify timing system that somebody wrote to the decrementer
void DecrementerSet();
u32 GetFakeDecrementer();
void TimeBaseSet();
u64 GetFakeTimeBase();
// Custom RTC
s64 GetLocalTimeRTCOffset();
// Returns an estimate of how fast/slow the emulation is running (excluding throttling induced sleep
// time). The estimate is computed over the last 1s of emulated time. Example values:
//
// - 0.5: the emulator is running at 50% speed (falling behind).
// - 1.0: the emulator is running at 100% speed.
// - 2.0: the emulator is running at 200% speed (or 100% speed but sleeping half of the time).
double GetEstimatedEmulationPerformance();
} // namespace SystemTimers
inline namespace SystemTimersLiterals
{
/// Converts timebase ticks to clock ticks.
constexpr SystemTimers::TimeBaseTick operator""_tbticks(unsigned long long value)
{
return SystemTimers::TimeBaseTick(value);
}
} // namespace SystemTimersLiterals