Clock Timing For Parallel Interleaved Data - Keysight Technologies N5171B EXG User Manual

Clock Timing for Parallel Interleaved Data

The N5102A module provides the capability to interleave the digital I and Q samples. There are two
choices for interleaving:
— IQ, where the I sample is transmitted first
— QI, where the Q sample is transmitted first
When parallel interleaved is selected, all samples are transmitted on the I data lines. This effectively
transmits the same number of samples during a sample period on half the number of data lines as
compared to non-interleaved samples. (A sample period consists of an I and Q sample.) Clocks per
sample is still a valid parameter for parallel interleaved transmissions and creates a reduction in the
sample rate relative to the clock rate. The clocks per sample selection is the ratio of the reduction.
Figure 10-5 shows each of the clocks per sample selections, for a parallel IQ interleaved port
configuration, using a word sized of four bits and the clock timing relative to the I and Q samples.
For a parallel QI interleaved port configuration, just reverse the I and Q sample positions. For input
mode, the clocks per sample setting is always one.
Figure 10-5 Clock Timing for a Parallel IQ Interleaved Port Configuration
The I sample is transmitted on one clock transition and the Q sample is transmitted on the
other transition; the sample and clock rates are the same.
1 Sample Period
1 Clock
Clock
Q sample
I sample
4 bits per word 4 bits per word
Keysight EXG and MXG X-Series Signal Generators User's Guide
1 Clock Per Sample
Digital Signal Interface Module (Option 003/004)
Clock Timing
293