41
bit 10
the leading/both edge recording bit (from register 0).
0 = leading only, 1 = both
bits 11-13
the event serial number (modulo 8)
bit 14
always 1 (identifies double word readout)
bit 15
always 1, identifies header word
FIRST DATA WORD
bits 0-7
8 bit data value
bit 8
1, indicates that the data is the most significant byte.
bit 9
Identifies the edge, 0 = leading, 1 = trailing
bits 10-14
5 bit channel number
bit 15
always 0, identifies data word
SECOND DATA WORD
bits 0-7 8 bit data value
bit 8
0, indicates that the data is the least significant byte.
bit 9
identifies edge, 0 = leading, 1 = trailing
bits 10-14
5 bit channel number
SUPPRESSING THE
HEADER
The Header mode bit, register 0, bit 13, when set to 1, allows suppress-
ing the header word if there is no data in the event. This is effective in all
readout modes, single or double word, buffered or unbuffered, CAMAC
or FERA. The event is not suppressed, only the header, so the event
ordering remains correctly synchronized among multiple 3377 modules.
If the channel occupancy is low, the use of this feature can result in a
reduction in the size of the data block for each event, and a small de-
crease in readout time (not the same as the dead time). It is recom-
mended that the last module in a readout group be set to always supply
the header (bit 13 set to 0).
