Pixie-32 User Manual
Version 0.2
If trace recording is enabled, trace data will immediately follow the last word of the event header.
Since raw ADC data points are 12-bit numbers, two 12-bit numbers are packed into one 32-bit word, as
shown below. Since the event header could have variable length depending on the selection of various
output data options, the header length, event length and trace length that are recorded in the first 4 words
of the event header should be used to navigate through the output data stream.
Inde
x
Data
Description
n
[31:0]
Last word of event header which could be 4 or 8
words long
Last word of event header
n+1
[31:28]
[27:16]
[15:12]
[11:0]
Packing of ADC Data #0 and #1
Not
used
ADC Data
#1
Not
used
ADC Data
#0
n+2
[31:28]
[27:16]
[15:12]
[11:0]
Packing of ADC Data #2 and #3
Not
used
ADC Data
#3
Not
used
ADC Data
#2
…
…
Statistics file format
Currently reported statistics registers: livetime, fast peaks, number of events.
●
2 32-bit words per statistics register.
●
3 statistics registers per channel.
●
32 channels: 192 32-bit words total.
●
Per each channel:
○
Register 0, word 0: [31:26] channel number, [25:16] fixed value 17, [15:0] live time bits
0--15
○
Register 0, word 1: [31:0] live time bits 16--48
○
To get live time in seconds, multiply by 16*20*10^(-9)
○
Register 1, word 0: [31:26] channel number, [25:16] fixed value 19, [15:0] fast peaks bits
0--15
○
Register 1, word 1: [31:0] fast peaks bits 16--48
○
Fast peaks is number of fast filter triggers (before pileup inspection, etc.)
○
Register 2, word 0: [31:26] channel number, [25:16] fixed value 21, [15:0] number of
events bits 0--15
○
Register 2, word 1: [31:0] number of events bits 16--48
○
Number of events is number of events passed to the host for recording.
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