3.2 Continuous Simultaneous acquisition and Readout (CSR)
U5303A User's Manual
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The sustainable data rate only depends on the number of recorded samples / bytes before starting
reading. Optimized acquisition data rate with CSR is close to maximum PCIe performance, resulting
in less than 5% below PCIe maximum data rate.
When an overflow occurs the writing to the stream buffers are disabled and the already acquired
data is still valid and can be read-out.
Data format
Default mode
By default, after acquisition, the 12-bit raw data are formatted as 16-bit data.
12-bit, 10-bit or 8-bit mode
Enabling 12-bit, 10-bit or 8-bit mode decreases the data rate and allows more parallel streaming
channels.
Example
The Table below gives the resulting data throughput, depending on the sampling rate and the data
format.
U5303A
SR1 (1 GS/s)
SR2 (1.6 GS/s)
default mode (12-bit raw on 16-bit)
2 GB/s
3.2 GB/s
12-bit mode
1.5 GB/s
2.4 GB/s
10-bit mode
1.25 GB/s
2 GB/s
8-bit mode
1 GB/s
1.6 GB/s
Emulation mode
With CSR, the data rate that can be sustained without overflow depends on multiple parameters of the
system where the card is plugged.
The data emulation mode allows to check the maximum data rate supported by the system where the
card is plugged (See driver function
DataEmulationEnabled
,
DataEmulationRate
).
Knowing that, the user is able to configure the acquisition settings to achieve a continuous
simultaneous acquisition and readout without overflow.
The emulation data sample rate can be reduced down from the card maximal sample rate (IMSR) to
any integer multiple of IMSR/512.
Notes:
• StreamSamples can be “StreamCh1” or “StreamCh2”; the application can choose to
read one or the other or both.
• StreamMarkers can only be “StreamTriggers”; the application can choose to read it or
not.
