4.4 Data encoding for TDC hits¶

The following bit table shows the encoding of the payload data (crono_packet::data) of all recorded TDC hits within the time-frame given by ndigo6g12_param_info::tdc_rollover_period.

Bit	31	30	…	9	8	7	6	5	4	3	2	1	0
Data	Timestamp					TDC hit flags				Channel number
Details	The timestamp is relative to `crono_packet::timestamp` and is given in units of `ndigo6g12_param_info::tdc_period`.					See below.				`0x0`: TDC channel 1 `0x1`: TDC channel 2 `0x2`: TDC channel 3 `0x3`: TDC channel 4 `0x4`: TRG `0x5`: GATE `0xD`: Dummy data `0xF`: Rollover marker

The TDC hit flags are one of the following:

NDIGO6G12_TDC_HIT_FLAG_LOST¶: At least one preceding event was lost due to full FIFO.

NDIGO6G12_TDC_HIT_FLAG_ROLLOVER_LOST¶

Rollover has been lost due to full FIFO.

Results in a fatal error.

NDIGO6G12_TDC_HIT_FLAG_GROUP_TIME_ROLLOVER¶

Timestamp is a rollover marker.

Add ndigo6g12_param_info::tdc_rollover_period to all subsequent timestamps in the packet.

NDIGO6G12_TDC_PADDING_DATA_CHANNEL¶

TDC hit channel number for padding-data.

Padding-data can be ignored. Does not contain any usefull information. Padding-data has NDIGO6G12_TDC_HIT_FLAG_GROUP_TIME_ROLLOVER and NDIGO6G12_TDC_HIT_FLAG_VALID always cleared.

NDIGO6G12_TDC_ROLLOVER_CHANNEL¶

TDC hit channel number for rollover marker.