Analog Devices ADRV9005 Reference Manual page 175

Reference Manual ADRV9001
TRANSMITTER/RECEIVER/OBSERVATION RECEIVER SIGNAL CHAIN CALIBRATIONS
Figure 160. Tracking Tx/Rx Calibration Configuration Through TES
When an automated TDD configuration is used based on the TDD frame length, some of the tracking calibrations are automatically disabled
in TES if the Rx/Tx frame length is less than 1 ms. If the receiver frame is less than 1 ms, RX_HD2, and RX_QEC_WBPOLY are disabled.
If the transmitter frame length is less than 1 ms, TX_DPD_CLGC, TX_QEC, and TX_LO_LEAKAGE are disabled. This ensures the correct
TDD operations with the user-provided TDD timing parameters. Therefore, it is recommended to follow the same requirement when configuring
tracking calibrations in own software. To violate this rule for better possible performance, carefully evaluate the tracking configurations with a
long TDD stability test.
Tracking Calibrations Scheduling
Tracking calibration scheduling refers to when the tracking calibrations will run based on the profile configurations. Tracking calibrations
scheduling is handled differently in TDD and FDD profiles.
For FDD profiles, the tracking calibrations will run periodically while in the RF_ENABLED state. No user interaction is needed to perform the
tracking calibrations.
For TDD profiles, including frequency hopping, the tracking calibrations will only run at the start of a frame. No user interaction is needed to
perform the tracking calibrations but note that since tracking calibrations will only run at the start of a frame, tracking calibrations won't run
periodically during a frame which might be significant for long frame times. The exception to this is the DPD/CLGC tracking calibrations as
described in the DPD/CLGC Updates Scheduling section.
As described in the Transmitter/Receiver/Observation Receiver Signal Chain Calibrations section, the observational receiver (ORx) path is
needed to perform the corresponding Tx tracking calibrations i.e. Tx1 uses ORx1 and Tx2 uses ORx2. User control of the ORx path will take
priority over the tracking calibrations. This means that if the user is taking control of the ORx path, no Tx calibrations can run. In a case where it
is needed to have user control of the ORx path as well as running Tx calibrations, a time-sharing scenario can be used.
For FDD profiles, the user can periodically take control of the ORx path (via raising the ORx enable pin) and when the user is not controlling
the ORx path, the tracking calibrations will automatically resume. For TDD profiles, the user can take control of the ORx path for specific
frames and frames where the user is not using the ORx path, tracking calibrations can run. For long frame times, it is possible to allow tracking
calibrations at the start of a frame and then the user can take control of the ORx path for the remainder of the frame. In this case, tracking
calibrations will need control of the ORx path for at least 2.2 ms at the start of the frame.
analog.com Rev. A | 175 of 377