diff --git a/src/core/gpu.cpp b/src/core/gpu.cpp
index 355940c92..c5d917617 100644
--- a/src/core/gpu.cpp
+++ b/src/core/gpu.cpp
@@ -65,8 +65,6 @@ void GPU::SoftReset()
m_draw_mode.SetTextureWindow(0);
UpdateDMARequest();
UpdateCRTCConfig();
-
- m_tick_event->Deactivate();
UpdateSliceTicks();
}
@@ -291,8 +289,13 @@ void GPU::DMAWrite(const u32* words, u32 word_count)
{
Assert(m_blitter_ticks == 0);
m_blitter_ticks = GetPendingGPUTicks() + word_count;
+
+ // reschedule GPU tick event
+ const TickCount sysclk_ticks = GPUTicksToSystemTicks(word_count);
+ if (m_tick_event->GetTicksUntilNextExecution() > sysclk_ticks)
+ m_tick_event->Schedule(sysclk_ticks);
+
UpdateDMARequest();
- UpdateSliceTicks();
}
}
break;
@@ -434,12 +437,6 @@ void GPU::UpdateCRTCConfig()
UpdateSliceTicks();
}
-static TickCount GPUTicksToSystemTicks(TickCount gpu_ticks)
-{
- // convert to master clock, rounding up as we want to overshoot not undershoot
- return static_cast<TickCount>((static_cast<u32>(gpu_ticks) * 7u + 10u) / 11u);
-}
-
TickCount GPU::GetPendingGPUTicks() const
{
const TickCount pending_sysclk_ticks = m_tick_event->GetTicksSinceLastExecution();
@@ -462,7 +459,6 @@ void GPU::UpdateSliceTicks()
m_tick_event->Schedule(
GPUTicksToSystemTicks((m_blitter_ticks > 0) ? std::min(m_blitter_ticks, ticks_until_vblank) : ticks_until_vblank));
- m_tick_event->SetPeriod(GPUTicksToSystemTicks(ticks_until_hblank));
}
bool GPU::IsRasterScanlinePending() const
@@ -479,14 +475,14 @@ void GPU::Execute(TickCount ticks)
m_crtc_state.fractional_ticks = ticks_mul_11 % 7;
m_crtc_state.current_tick_in_scanline += gpu_ticks;
- if (m_blitter_ticks > 0)
+ // handle blits
+ TickCount blit_ticks_remaining = gpu_ticks;
+ while (m_blitter_ticks > 0 && blit_ticks_remaining > 0)
{
- m_blitter_ticks -= gpu_ticks;
- if (m_blitter_ticks <= 0)
- {
- m_blitter_ticks = 0;
- UpdateDMARequest();
- }
+ const TickCount slice = std::min(blit_ticks_remaining, m_blitter_ticks);
+ m_blitter_ticks -= slice;
+ blit_ticks_remaining -= slice;
+ UpdateDMARequest();
}
}
@@ -636,6 +632,7 @@ void GPU::WriteGP1(u32 value)
case 0x00: // Reset GPU
{
Log_DebugPrintf("GP1 reset GPU");
+ Synchronize();
SoftReset();
}
break;
@@ -647,6 +644,7 @@ void GPU::WriteGP1(u32 value)
m_command_total_words = 0;
m_vram_transfer = {};
m_GP0_buffer.clear();
+ m_blitter_ticks = 0;
UpdateDMARequest();
}
break;
@@ -662,7 +660,7 @@ void GPU::WriteGP1(u32 value)
{
const bool disable = ConvertToBoolUnchecked(value & 0x01);
Log_DebugPrintf("Display %s", disable ? "disabled" : "enabled");
- m_tick_event->InvokeEarly();
+ Synchronize();
m_GPUSTAT.display_disable = disable;
}
break;
@@ -690,7 +688,7 @@ void GPU::WriteGP1(u32 value)
if (m_crtc_state.regs.horizontal_display_range != new_value)
{
- m_tick_event->InvokeEarly(true);
+ Synchronize();
m_crtc_state.regs.horizontal_display_range = new_value;
UpdateCRTCConfig();
}
@@ -704,7 +702,7 @@ void GPU::WriteGP1(u32 value)
if (m_crtc_state.regs.vertical_display_range != new_value)
{
- m_tick_event->InvokeEarly(true);
+ Synchronize();
m_crtc_state.regs.vertical_display_range = new_value;
UpdateCRTCConfig();
}
@@ -739,7 +737,7 @@ void GPU::WriteGP1(u32 value)
if (m_GPUSTAT.bits != new_GPUSTAT.bits)
{
- m_tick_event->InvokeEarly(true);
+ Synchronize();
m_GPUSTAT.bits = new_GPUSTAT.bits;
UpdateCRTCConfig();
}
diff --git a/src/core/gpu.h b/src/core/gpu.h
index eab1de2aa..bc8319fac 100644
--- a/src/core/gpu.h
+++ b/src/core/gpu.h
@@ -133,6 +133,12 @@ public:
void DMARead(u32* words, u32 word_count);
void DMAWrite(const u32* words, u32 word_count);
+ /// Returns the number of pending GPU ticks.
+ TickCount GetPendingGPUTicks() const;
+
+ /// Returns true if enough ticks have passed for the raster to be on the next line.
+ bool IsRasterScanlinePending() const;
+
// Synchronizes the CRTC, updating the hblank timer.
void Synchronize();
@@ -152,6 +158,12 @@ public:
static std::unique_ptr<GPU> CreateSoftwareRenderer();
protected:
+ static TickCount GPUTicksToSystemTicks(TickCount gpu_ticks)
+ {
+ // convert to master clock, rounding up as we want to overshoot not undershoot
+ return static_cast<TickCount>((static_cast<u32>(gpu_ticks) * 7u + 10u) / 11u);
+ }
+
// Helper/format conversion functions.
static constexpr u8 Convert5To8(u8 x5) { return (x5 << 3) | (x5 & 7); }
static constexpr u8 Convert8To5(u8 x8) { return (x8 >> 3); }
@@ -311,12 +323,6 @@ protected:
// Ticks for hblank/vblank.
void Execute(TickCount ticks);
- /// Returns the number of pending GPU ticks.
- TickCount GetPendingGPUTicks() const;
-
- /// Returns true if enough ticks have passed for the raster to be on the next line.
- bool IsRasterScanlinePending() const;
-
/// Returns true if scanout should be interlaced.
bool IsDisplayInterlaced() const { return !m_force_progressive_scan && m_GPUSTAT.In480iMode(); }
diff --git a/src/core/timers.cpp b/src/core/timers.cpp
index 4704c405c..124895220 100644
--- a/src/core/timers.cpp
+++ b/src/core/timers.cpp
@@ -166,10 +166,10 @@ u32 Timers::ReadRegister(u32 offset)
{
case 0x00:
{
- if (timer_index < 2)
+ if (timer_index < 2 && cs.external_counting_enabled)
{
// timers 0/1 depend on the GPU
- if (cs.external_counting_enabled)
+ if (timer_index == 0 || m_gpu->IsRasterScanlinePending())
m_gpu->Synchronize();
}
@@ -180,10 +180,10 @@ u32 Timers::ReadRegister(u32 offset)
case 0x04:
{
- if (timer_index < 2)
+ if (timer_index < 2 && cs.external_counting_enabled)
{
// timers 0/1 depend on the GPU
- if (cs.external_counting_enabled)
+ if (timer_index == 0 || m_gpu->IsRasterScanlinePending())
m_gpu->Synchronize();
}
@@ -211,8 +211,13 @@ void Timers::WriteRegister(u32 offset, u32 value)
CounterState& cs = m_states[timer_index];
- if (timer_index < 2)
- m_gpu->Synchronize();
+ if (timer_index < 2 && cs.external_counting_enabled)
+ {
+ // timers 0/1 depend on the GPU
+ if (timer_index == 0 || m_gpu->IsRasterScanlinePending())
+ m_gpu->Synchronize();
+ }
+
m_sysclk_event->InvokeEarly();
switch (port_offset)
diff --git a/src/core/timing_event.cpp b/src/core/timing_event.cpp
index ed3000b3b..94903d260 100644
--- a/src/core/timing_event.cpp
+++ b/src/core/timing_event.cpp
@@ -74,7 +74,7 @@ void TimingEvent::InvokeEarly(bool force /* = false */)
if (!m_active)
return;
- const TickCount pending_ticks = m_system->m_running_events ? 0 : m_system->m_cpu->GetPendingTicks();
+ const TickCount pending_ticks = m_system->m_cpu->GetPendingTicks();
const TickCount ticks_to_execute = m_time_since_last_run + pending_ticks;
if (!force && ticks_to_execute < m_period)
return;
@@ -93,7 +93,7 @@ void TimingEvent::Activate()
return;
// leave the downcount intact
- const TickCount pending_ticks = m_system->m_running_events ? 0 : m_system->m_cpu->GetPendingTicks();
+ const TickCount pending_ticks = m_system->m_cpu->GetPendingTicks();
m_downcount += pending_ticks;
m_time_since_last_run -= pending_ticks;
@@ -106,7 +106,7 @@ void TimingEvent::Deactivate()
if (!m_active)
return;
- const TickCount pending_ticks = m_system->m_running_events ? 0 : m_system->m_cpu->GetPendingTicks();
+ const TickCount pending_ticks = m_system->m_cpu->GetPendingTicks();
m_downcount -= pending_ticks;
m_time_since_last_run += pending_ticks;