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EE/IOP Timers: Rewrote most of the gate handling to be better.
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@refractionpcsx2
refractionpcsx2 committed Apr 29, 2024
1 parent 4363255 commit 5f7c2b7
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Showing 6 changed files with 229 additions and 283 deletions.
142 changes: 60 additions & 82 deletions pcsx2/Counters.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -21,9 +21,7 @@
#include "VMManager.h"
#include "VUmicro.h"

extern u8 psxhblankgate;
static const uint EECNT_FUTURE_TARGET = 0x10000000;
static int gates = 0;

uint g_FrameCount = 0;

Expand Down Expand Up @@ -75,7 +73,7 @@ static __fi void _rcntSet(int cntidx)
const Counter& counter = counters[cntidx];

// Stopped or special hsync gate?
if (!counter.mode.IsCounting || (counter.mode.ClockSource == 0x3))
if (!rcntCanCount(cntidx) || (counter.mode.ClockSource == 0x3))
return;

if (!counter.mode.TargetInterrupt && !counter.mode.OverflowInterrupt)
Expand Down Expand Up @@ -232,7 +230,7 @@ static void vSyncInfoCalc(vSyncTimingInfo* info, double framesPerSecond, u32 sca
{
hBlank /= 2;
hRender /= 2;
}
}

//TODO: Carry fixed-point math all the way through the entire vsync and hsync counting processes, and continually apply rounding
//as needed for each scheduled v/hsync related event. Much better to handle than this messed state.
Expand Down Expand Up @@ -512,8 +510,7 @@ static __fi void VSyncStart(u32 sCycle)
// Memcard IO detection - Uses a tick system to determine when memcards are no longer being written.
MemcardBusy::Decrement();

if (gates)
rcntStartGate(true, sCycle); // Counters Start Gate code
rcntStartGate(true, sCycle); // Counters Start Gate code

// INTC - VB Blank Start Hack --
// Hack fix! This corrects a freezeup in Granda 2 where it decides to spin
Expand Down Expand Up @@ -570,8 +567,7 @@ static __fi void VSyncEnd(u32 sCycle)

hwIntcIrq(INTC_VBLANK_E); // HW Irq
psxVBlankEnd(); // psxCounters vBlank End
if (gates)
rcntEndGate(true, sCycle); // Counters End Gate Code
rcntEndGate(true, sCycle); // Counters End Gate Code

// FolderMemoryCard needs information on how much time has passed since the last write
// Call it every 60 frames
Expand All @@ -597,13 +593,14 @@ __fi void rcntUpdate_hScanline()
//iopEventAction = 1;
if (hsyncCounter.Mode == MODE_HBLANK)
{ //HBLANK Start

rcntStartGate(false, hsyncCounter.sCycle + hsyncCounter.CycleT);
psxHBlankStart();

// Setup the hRender's start and end cycle information:
hsyncCounter.sCycle += vSyncInfo.hBlank; // start (absolute cycle value)
hsyncCounter.CycleT = vSyncInfo.hRender; // endpoint (delta from start value)
hsyncCounter.Mode = MODE_HRENDER;

rcntStartGate(false, hsyncCounter.sCycle);
psxCheckStartGate16(0);
}
else
{ //HBLANK END / HRENDER Begin
Expand All @@ -614,16 +611,15 @@ __fi void rcntUpdate_hScanline()
gsIrq();
}

rcntEndGate(false, hsyncCounter.sCycle + hsyncCounter.CycleT);

psxHBlankEnd();

// set up the hblank's start and end cycle information:
hsyncCounter.sCycle += vSyncInfo.hRender; // start (absolute cycle value)
hsyncCounter.CycleT = vSyncInfo.hBlank; // endpoint (delta from start value)
hsyncCounter.Mode = MODE_HBLANK;

if (gates)
rcntEndGate(false, hsyncCounter.sCycle);
if (psxhblankgate)
psxCheckEndGate16(0);

#ifdef VSYNC_DEBUG
hsc++;
#endif
Expand All @@ -637,11 +633,11 @@ __fi void rcntUpdate_vSync()

if (vsyncCounter.Mode == MODE_VSYNC)
{
VSyncEnd(vsyncCounter.sCycle + vsyncCounter.CycleT);

vsyncCounter.sCycle += vSyncInfo.Blank;
vsyncCounter.CycleT = vSyncInfo.Render;
vsyncCounter.Mode = MODE_VRENDER;

VSyncEnd(vsyncCounter.sCycle);
vsyncCounter.Mode = MODE_VRENDER; // VSYNC END - Render begin
}
else if (vsyncCounter.Mode == MODE_GSBLANK) // GS CSR Swap and interrupt
{
Expand All @@ -651,17 +647,17 @@ __fi void rcntUpdate_vSync()
// Don't set the start cycle, makes it easier to calculate the correct Vsync End time
vsyncCounter.CycleT = vSyncInfo.Blank;
}
else // VSYNC end / VRENDER begin
else // VSYNC Start
{
VSyncStart(vsyncCounter.sCycle + vsyncCounter.CycleT);

vsyncCounter.sCycle += vSyncInfo.Render;
vsyncCounter.CycleT = vSyncInfo.GSBlank;
vsyncCounter.Mode = MODE_GSBLANK;

// Accumulate hsync rounding errors:
hsyncCounter.sCycle += vSyncInfo.hSyncError;

VSyncStart(vsyncCounter.sCycle);

#ifdef VSYNC_DEBUG
vblankinc++;
if (vblankinc > 1)
Expand Down Expand Up @@ -717,7 +713,20 @@ static __fi void _cpuTestOverflow(int i)
}


// forceinline note: this method is called from two locations, but one
__fi bool rcntCanCount(int i)
{
if (!counters[i].mode.IsCounting)
return false;

if (!counters[i].mode.EnableGate)
return true;

// If we're in gate mode, we can only count if it's not both gated and counting on HBLANK or GateMode is not 0 (Count only when low) or the signal is low.
return ((counters[i].mode.GateSource == 0 && counters[i].mode.ClockSource != 3 && (hsyncCounter.Mode == MODE_HRENDER || counters[i].mode.GateMode != 0)) ||
(counters[i].mode.GateSource == 1 && (vsyncCounter.Mode == MODE_VRENDER || counters[i].mode.GateMode != 0)));
}

// forceinline note: this method is called from two locations, but one
// of them is the interpreter, which doesn't count. ;) So might as
// well forceinline it!
__fi void rcntUpdate()
Expand All @@ -730,12 +739,7 @@ __fi void rcntUpdate()

for (int i = 0; i <= 3; i++)
{
// We want to count gated counters (except the hblank which exclude below, and are
// counted by the hblank timer instead)

//if ( gates & (1<<i) ) continue;

if (!counters[i].mode.IsCounting)
if (!rcntCanCount(i))
continue;

if (counters[i].mode.ClockSource != 0x3) // don't count hblank sources
Expand All @@ -761,34 +765,21 @@ static __fi void _rcntSetGate(int index)
if (counters[index].mode.EnableGate)
{
// If the Gate Source is hblank and the clock selection is also hblank
// then the gate is disabled and the counter acts as a normal hblank source.

// the timer completely turns off (HW Tested).
if (!(counters[index].mode.GateSource == 0 && counters[index].mode.ClockSource == 3))
{
EECNT_LOG("EE Counter[%d] Using Gate! Source=%s, Mode=%d.",
index, counters[index].mode.GateSource ? "vblank" : "hblank", counters[index].mode.GateMode);

gates |= (1 << index);
// FIXME: Test required - should the counter be stopped here? I feel like it should only stop and reset on the gate signal happening.
counters[index].mode.IsCounting = 0;
return;
}
else
EECNT_LOG("EE Counter[%d] GATE DISABLED because of hblank source.", index);
}

gates &= ~(1 << index);
}

// mode - 0 means hblank source, 8 means vblank source.
static __fi void rcntStartGate(bool isVblank, u32 sCycle)
{
int i;

for (i = 0; i <= 3; i++)
for (int i = 0; i < 4; i++)
{
//if ((mode == 0) && ((counters[i].mode & 0x83) == 0x83))
if (!isVblank && counters[i].mode.IsCounting && (counters[i].mode.ClockSource == 3))
if (!isVblank && (counters[i].mode.ClockSource == 3) && rcntCanCount(i))
{
// Update counters using the hblank as the clock. This keeps the hblank source
// nicely in sync with the counters and serves as an optimization also, since these
Expand All @@ -802,35 +793,31 @@ static __fi void rcntStartGate(bool isVblank, u32 sCycle)
_cpuTestTarget(i);
}

if (!(gates & (1 << i)))
if (!counters[i].mode.EnableGate)
continue;

if ((!!counters[i].mode.GateSource) != isVblank)
continue;

switch (counters[i].mode.GateMode)
{
case 0x0: //Count When Signal is low (off)
case 0x0: //Count When Signal is low (V_RENDER ONLY)

// Just set the start cycle (sCycleT) -- counting will be done as needed
// for events (overflows, targets, mode changes, and the gate off below)

counters[i].count = rcntRcount(i);
counters[i].mode.IsCounting = 0;
counters[i].sCycleT = sCycle;
EECNT_LOG("EE Counter[%d] %s StartGate Type0, count = %x", i,
isVblank ? "vblank" : "hblank", counters[i].count);
break;

case 0x2: // reset and start counting on vsync end
// this is the vsync start so do nothing.
case 0x2: // Reset on Vsync end
// This is the vsync start so do nothing.
break;

case 0x1: //Reset and start counting on Vsync start
case 0x3: //Reset and start counting on Vsync start and end
counters[i].mode.IsCounting = 1;
case 0x1: // Reset on Vsync start
case 0x3: // Reset on Vsync start and end
counters[i].count = 0;
counters[i].target &= 0xffff;
counters[i].sCycleT = sCycle;
EECNT_LOG("EE Counter[%d] %s StartGate Type%d, count = %x", i,
isVblank ? "vblank" : "hblank", counters[i].mode.GateMode, counters[i].count);
break;
Expand All @@ -848,41 +835,33 @@ static __fi void rcntStartGate(bool isVblank, u32 sCycle)
// mode - 0 means hblank signal, 8 means vblank signal.
static __fi void rcntEndGate(bool isVblank, u32 sCycle)
{
int i;

for (i = 0; i <= 3; i++)
{ //Gates for counters
if (!(gates & (1 << i)))
for (int i = 0; i < 4; i++)
{
if (!counters[i].mode.EnableGate)
continue;

if ((!!counters[i].mode.GateSource) != isVblank)
continue;

switch (counters[i].mode.GateMode)
{
case 0x0: //Count When Signal is low (off)

// Set the count here. Since the timer is being turned off it's
// important to record its count at this point (it won't be counted by
// calls to rcntUpdate).
counters[i].mode.IsCounting = 1;
counters[i].sCycleT = cpuRegs.cycle;
case 0x0: //Count When Signal is low (V_RENDER ONLY)
counters[i].sCycleT = sCycle;

EECNT_LOG("EE Counter[%d] %s EndGate Type0, count = %x", i,
isVblank ? "vblank" : "hblank", counters[i].count);
break;

case 0x1: // Reset and start counting on Vsync start
// this is the vsync end so do nothing
case 0x1: // Reset on Vsync start
// This is the vsync end so do nothing
break;

case 0x2: //Reset and start counting on Vsync end
case 0x3: //Reset and start counting on Vsync start and end
counters[i].mode.IsCounting = 1;
case 0x2: // Reset on Vsync end
case 0x3: // Reset on Vsync start and end
EECNT_LOG("EE Counter[%d] %s EndGate Type%d, count = %x", i,
isVblank ? "vblank" : "hblank", counters[i].mode.GateMode, counters[i].count);
counters[i].count = 0;
counters[i].target &= 0xffff;
counters[i].sCycleT = sCycle;
EECNT_LOG("EE Counter[%d] %s EndGate Type%d, count = %x", i,
isVblank ? "vblank" : "hblank", counters[i].mode.GateMode, counters[i].count);
break;
}
}
Expand All @@ -892,7 +871,7 @@ static __fi void rcntEndGate(bool isVblank, u32 sCycle)

static __fi void rcntWmode(int index, u32 value)
{
if (counters[index].mode.IsCounting)
if (rcntCanCount(index))
{
if (counters[index].mode.ClockSource != 0x3)
{
Expand All @@ -909,7 +888,7 @@ static __fi void rcntWmode(int index, u32 value)

counters[index].modeval &= ~(value & 0xc00);
counters[index].modeval = (counters[index].modeval & 0xc00) | (value & 0x3ff);
EECNT_LOG("EE Counter[%d] writeMode = %x passed value=%x", index, counters[index].modeval, value);
EECNT_LOG("EE Counter[%d] writeMode = %x passed value=%x", index, counters[index].modeval, value);

switch (counters[index].mode.ClockSource) { //Clock rate divisers *2, they use BUSCLK speed not PS2CLK
case 0: counters[index].rate = 2; break;
Expand All @@ -927,7 +906,7 @@ static __fi void rcntWcount(int index, u32 value)
EECNT_LOG("EE Counter[%d] writeCount = %x, oldcount=%x, target=%x", index, value, counters[index].count, counters[index].target);

// re-calculate the start cycle of the counter based on elapsed time since the last counter update:
if (counters[index].mode.IsCounting)
if (rcntCanCount(index))
{
if (counters[index].mode.ClockSource != 0x3)
{
Expand Down Expand Up @@ -959,7 +938,7 @@ static __fi void rcntWtarget(int index, u32 value)
// If the target is behind the current count, set it up so that the counter must
// overflow first before the target fires:

if (counters[index].mode.IsCounting)
if (rcntCanCount(index))
{
if (counters[index].mode.ClockSource != 0x3)
{
Expand All @@ -986,7 +965,7 @@ __fi u32 rcntRcount(int index)
u32 ret;

// only count if the counter is turned on (0x80) and is not an hsync gate (!0x03)
if (counters[index].mode.IsCounting && (counters[index].mode.ClockSource != 0x3))
if (rcntCanCount(index) && (counters[index].mode.ClockSource != 0x3))
ret = counters[index].count + ((cpuRegs.cycle - counters[index].sCycleT) / counters[index].rate);
else
ret = counters[index].count;
Expand Down Expand Up @@ -1076,7 +1055,6 @@ bool SaveStateBase::rcntFreeze()
Freeze(vSyncInfo);
Freeze(gsVideoMode);
Freeze(gsIsInterlaced);
Freeze(gates);

if (IsLoading())
cpuRcntSet();
Expand Down
7 changes: 4 additions & 3 deletions pcsx2/Counters.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,9 +22,9 @@ struct EECNT_MODE
u32 GateSource:1;

// 0 - count when the gate signal is low
// 1 - reset and start counting at the signal's rising edge (h/v blank end)
// 2 - reset and start counting at the signal's falling edge (h/v blank start)
// 3 - reset and start counting at both signal edges
// 1 - reset at the signal's rising edge (h/v blank start)
// 2 - reset at the signal's falling edge (h/v blank end)
// 3 - reset at both signal edges
u32 GateMode:2;

// Counter cleared to zero when target reached.
Expand Down Expand Up @@ -126,6 +126,7 @@ extern uint g_FrameCount;

extern void rcntUpdate_hScanline();
extern void rcntUpdate_vSync();
extern bool rcntCanCount(int i);
extern void rcntUpdate();

extern void rcntInit();
Expand Down
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