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SAM TC: Implement capture mode, configurable counter width #200

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SAM TC: Implement capture mode, configurable counter width #200

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3e24670
SAM_TC: Implement capture mode as free-running counter
msarehn Mar 18, 2026
31f0c51
SAM_TC: Add configurable counter width (16/32-bit)
msarehn Mar 18, 2026
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42 changes: 24 additions & 18 deletions src/Emulator/Peripherals/Peripherals/Timers/SAM_TC.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -18,13 +18,14 @@ namespace Antmicro.Renode.Peripherals.Timers
{
public class SAM_TC : BasicDoubleWordPeripheral, INumberedGPIOOutput, IKnownSize
{
public SAM_TC(IMachine machine, ulong masterClockFrequency = 20000000) : base(machine)
public SAM_TC(IMachine machine, ulong masterClockFrequency = 20000000, int counterWidth = 16) : base(machine)
{
var connections = new Dictionary<int, IGPIO>();
channels = new Channel[NumberOfChannels];
var maxValue = counterWidth == 32 ? 0xFFFFFFFFUL : 0xFFFFUL;
for(int i = 0; i < NumberOfChannels; i++)
{
channels[i] = new Channel(machine.ClockSource, masterClockFrequency, this, i);
channels[i] = new Channel(machine.ClockSource, masterClockFrequency, this, i, maxValue);
connections[i] = channels[i].IRQ;
}
Connections = new ReadOnlyDictionary<int, IGPIO>(connections);
Expand Down Expand Up @@ -323,14 +324,15 @@ public enum Registers

private class Channel
{
public Channel(IClockSource clockSource, ulong masterClockFrequency, IPeripheral owner, int channel)
public Channel(IClockSource clockSource, ulong masterClockFrequency, IPeripheral owner, int channel, ulong maxValue = DefaultMaxValue)
{
this.masterClockFrequency = masterClockFrequency;
this.maxValue = maxValue;
this.channel = channel;
parent = owner;
IRQ = new GPIO();
timer = new LimitTimer(clockSource, masterClockFrequency, owner, $"channel-{channel}", MaxValue, Direction.Ascending, eventEnabled: true, divider: 2);
cTimer = new LimitTimer(clockSource, masterClockFrequency, owner, $"channel-{channel} C capture", MaxValue, Direction.Ascending, workMode: WorkMode.OneShot, eventEnabled: true, divider: 2);
timer = new LimitTimer(clockSource, masterClockFrequency, owner, $"channel-{channel}", maxValue, Direction.Ascending, eventEnabled: true, divider: 2);
cTimer = new LimitTimer(clockSource, masterClockFrequency, owner, $"channel-{channel} C capture", maxValue, Direction.Ascending, workMode: WorkMode.OneShot, eventEnabled: true, divider: 2);
timer.LimitReached += LimitReached;
cTimer.LimitReached += delegate
{
Expand Down Expand Up @@ -571,18 +573,20 @@ private void UpdateTimer(bool start = false)

if(!waveformMode)
{
parent.ErrorLog("Unimplemented");
// Capture mode: free-running counter up to MaxValue
timer.Direction = Direction.Ascending;
timer.Limit = maxValue;
}
else
{
switch(waveformSelected)
{
case WaveSelection.Up:
timer.Direction = Direction.Ascending;
timer.Limit = MaxValue;
timer.Limit = maxValue;
break;
case WaveSelection.UpDown:
timer.Limit = MaxValue;
timer.Limit = maxValue;
break;
case WaveSelection.UpRC:
timer.Direction = Direction.Ascending;
Expand All @@ -602,15 +606,15 @@ private void UpdateTimer(bool start = false)

private void UpdateCTimer()
{
if(!enabled || !waveformMode)
if(!enabled)
{
cTimer.Enabled = false;
return;
}
switch(waveformSelected)

// In capture mode or waveform Up/UpDown, use cTimer for RC compare
if(!waveformMode || waveformSelected == WaveSelection.Up || waveformSelected == WaveSelection.UpDown)
{
case WaveSelection.Up:
case WaveSelection.UpDown:
var direction = timer.Direction;
var value = timer.Value;
var limit = timer.Limit;
Expand All @@ -633,10 +637,10 @@ private void UpdateCTimer()
cTimer.Limit = limit - valueC;
}
cTimer.Enabled = timer.Enabled;
break;
default:
}
else
{
cTimer.Enabled = false;
break;
}
}

Expand All @@ -655,7 +659,8 @@ private void LimitReached()
}
if(!waveformMode)
{
parent.ErrorLog("Unimplemented");
// Capture mode: free-running counter overflow
overflow = true;
}
else
{
Expand All @@ -669,7 +674,7 @@ private void LimitReached()
compareCInterrupt = true;
break;
case WaveSelection.UpDown:
if(timer.Value == MaxValue)
if(timer.Value == maxValue)
{
parent.NoisyLog("Channel #{0} overflow", channel);
overflow = true;
Expand Down Expand Up @@ -718,7 +723,8 @@ private void LimitReached()
private readonly LimitTimer timer;
private readonly LimitTimer cTimer;

private const ulong MaxValue = 0xFFFF;
private readonly ulong maxValue;
private const ulong DefaultMaxValue = 0xFFFF;
}

private enum ClockSelection
Expand Down