•
TRIGGER TIME TAG
(bits[31:0] of 4
th
header word) is the 31-bit Trigger Time Tag (TTT) informa on
(31 bit counter and 32
nd
bit as roll-over flag), which is the trigger me reference. If the ETTT op on
is enabled, then this field becomes the 32 less significant bits of the 48-bit Extended Trigger Time Tag
informa on in addi on to the 16 bits (MSB) of the TRG OPTIONS field (2
nd
event word). Note that, in
the ETTT case, the roll-over flag is no more provided. The trigger me tag is reset either at the start
of acquisi on, or via front panel signal on S-IN or LVDS I/O connectors, and increments with 100 MHz
frequency (i.e. at each ADC clock cycle). The TTT value is read at half the frequency (i.e. 50 MHz) so
that the specifica ons are 20 ns resolu on and 21 s range (10 ns
×
(2
31
– 1)), which can be extended
to 781 h (10 ns
×
(2
48
– 1)) if ETTT is enabled.
Data
Data are the stored samples. Data from masked channels are not read.
Event Format Examples
Figure
shows the data format in case all the 4 channels are enabled, with Zero Length Encoding disabled
and enabled respec vely.
28
UM3247 - N6724 User Manual rev. 10
