Caen DT5740 - Multi-Event Memory Organization; Custom Size Events; Table 3.1: Buffer Organization

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User's Manual (MUT)
Mod. DT5740 32 Channel 12bit - 65MS/s Digitizer
04/05/2016
12
NPO:
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00100/09:5740x.MUTx/12
DT5740_REV12.DOC
50
24
3.3.3 Multi-Event Memory Organization
Each channel of the DT5740 features a SRAM memory to store the acquired events. The memory
size for the event storage is 192 kS/ch and it can be divided in a programmable number, N
b
, of
buffers (N
b
from 1 up to 1024) by the register address 0x800C, as described in Table 3.1 below.
Table 3.1: Buffer Organization
Register Value
Buffer Number
(N
b
)
SIZE of one BUFFER (samples)
SRAM 192kS/ch
0x0
1
192k
0x1
2
96k
0x2
4
48k
0x3
8
24k
0x4
16
12k
0x5
32
6k
0x6
64
3k
0x7
128
1536
0x8
256
768
0x9
512
384
0xA
1024
192
3.3.3.1 Custom Size Events
It is possible to make events with a number of samples, which depends on 0x8020 register
setting, smaller than the default value. This register’s value is given in number of memory
locations. According to the formula:
3*N
LOC
= 2*N
S
only values that are multiples of 3 are allowed for this register.
NOTE: The value of N
LOC
must be set in order that the relevant number of samples does not
exceed the buffer size and it mustn’t be modified while the acquisition is running. Even using the
custom size setting, the number of buffers and the buffer size are not affected by N
LOC
, but they
are still determined by N
b
.
The concepts of buffer organization and custom size directly affect the width of the acquisition
window (i.e. number of the digitized waveform samples per event). The Record Length
parameter defined in CAEN software (such as WaveDump and CAENScope introduced in § 5) and
the Set/GetRecordLength() functions of the CAENDigitizer library (see § 4.2) rely on these
concepts.