UG-1828
Preliminary Technical Data
Rev. PrC | Page 106 of 338
hopping, typically the frames are fairly short, therefore fast should be sufficient. The PLL calibration mode can be set with
adi_adrv9001_PllCalibration structure.
LO Muxing
For short transition times, ADRV9001 requires two LOs to be used in a ping pong operation. This means while one PLL is used for one
frame, the other PLL is being retuned for the next frame. During the transition time, the LOs are swapped.
LO muxing always uses 1 frame delay, examples shown in Figure 105.
HOP
RX_EN
TX_EN
RX_EN
TX_EN
RX
RX
RX
TX
HOP
RX
TX
RX
TX
TX
RX
TX
RX
TX
TX
Figure 105 LO Muxing Timing Diagram
LO Retune
For longer transition times, the PLL can be retuned for the starting frame within the transition time, if that time is greater than the sum of
the PLL lock time and channel bring up time.
LO retune always uses 0 frame delay, examples shown in Figure 106.
Figure 106 LO Retune Timing Diagram
PLL lock time is discussed in section LO Retune.
Currently user should rely on the actual test result on the LO retune time, with the evaluation platform, as currently the channel bring up
time is difficult to quantify because they differ in different cases.
Pre-Process Mode vs. Real-Time Process Mode
Pre-process Mode
refers to the frequency hopping tables being sent to ADRV9001 and processed before frequency hopping operation
begins.
Real-time Process Mode
refers to the frequency hopping table not being processed at initialization stage but at the hopping stage. At each
hop, the next entry in the table is read and processed. This allows the user to update the frequency hopping tables on the fly.
These two modes of operations are referring to the frequency hopping tables, and they will be explained in further detail in the frequency
hopping table sections
CHANNEL AND PROFILE SELECTION
Depending on the operation mode, operations of dual channel (2T2R, 2T, or 2R) diversity, or single channel (1T1R, 1T, or 1R) is
supported.
