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232 Chapter 7
Digital Signal Interface Module
Data Types
Data Types
The following block diagram indicates where in the ESG signal generation process the data is injected for
input mode or tapped for output mode.
Output Mode
When using an ARB format, the data type is always Samples and no filtering is applied to the data
samples.The samples are sent to the digital module at the ARB sample clock rate.
For real-time formats, choosing Samples as the data type will send filtered samples to the digital module at a
rate between 50 MHz and 100 MHz. Selecting Pre-FIR Samples, sends unfiltered samples to the digital
module at a rate equal to the sample rate of the current format.
Input Mode
When the data type is Samples, the data samples coming through the digital module are injected at a point
that bypasses the filtering process.
If Pre-FIR Samples is selected, the data samples are injected before the filtering process. The maximum rate
will be determined by the selected filter. Refer to
Table 7-7 .
Data
FIR
DACs
RF
Samples
Samples
Output
Samples
Samples
Pre-FIR
Mode
Filtering
I,Q
Modulator
LO
Input
Mode
Pre-FIR
ESG
Generator
I/Q