/** * @file TimeArrayGAM.h * @brief GAM that expands a scalar timer value into a per-sample uint32 time array. * @date 19/05/2026 * @author Martino Ferrari * * @details Each Execute() call reads one uint32 scalar input (time in microseconds, * e.g. from LinuxTimer) and fills a uint32[N] output array where element[k] holds * the reconstructed timestamp of sample k: * * Anchor = FirstSample: out[k] = input + k * period_us * Anchor = LastSample: out[k] = input - (N-1-k) * period_us * Anchor = Continuous: out[k] = input(first cycle) + (n + k) * period_us * * FirstSample/LastSample re-read the timer every cycle, so they propagate any * cycle the RT thread loses: LinuxTimer re-phases (counter += nCycles) and the * emitted time base jumps by a whole period while only one array of samples is * produced, leaving a hole. Continuous anchors once and then advances an * internal sample counter by N per cycle, which is what an acquisition card * with its own clock does — use it when the data signal is itself contiguous * (SineArrayGAM, for instance, never skips phase on a lost cycle). * * The resulting time array is suitable as the TimeSignal for a UDPStreamer signal * configured with TimeMode = FullArray, providing exact per-sample timestamps. * * Configuration: *
* +TimeArrayGAM1 = {
* Class = TimeArrayGAM
* SamplingRate = 1000000.0 // Sample rate in Hz (must match data signal)
* Anchor = FirstSample // FirstSample (default), LastSample or Continuous
* InputSignals = {
* Time = { DataSource = DDB; Type = uint32 }
* }
* OutputSignals = {
* TimeArray = { DataSource = DDB; Type = uint32; NumberOfElements = 1000 }
* }
* }
*
*
* Exactly one uint32 input signal and one uint32 output array are required.
*/
#ifndef TIMEARRAYGAM_H_
#define TIMEARRAYGAM_H_
#include "CompilerTypes.h"
#include "GAM.h"
namespace MARTe {
class TimeArrayGAM : public GAM {
public:
CLASS_REGISTER_DECLARATION()
TimeArrayGAM();
virtual ~TimeArrayGAM();
virtual bool Initialise(StructuredDataI &data);
virtual bool Setup();
virtual bool Execute();
private:
float64 samplingRate; /**< Sample rate [Hz] */
bool anchorIsFirst; /**< true = FirstSample anchor, false = LastSample */
bool anchorIsCont; /**< true = Continuous anchor (internal sample counter) */
bool contStarted; /**< Continuous: origin has been latched */
uint64 contOriginNs; /**< Continuous: timer value latched on the first cycle */
uint64 contSamples; /**< Continuous: samples emitted so far */
uint32 nElements; /**< Number of output elements */
uint32 *inputTime; /**< Pointer to scalar input (microseconds, uint32 from LinuxTimer) */
uint64 *outputBuf; /**< Pointer to output array (nanoseconds, uint64) */
};
} /* namespace MARTe */
#endif /* TIMEARRAYGAM_H_ */