EVAL-ADF7021DBZ5 Datasheet, PDF (41/64 Pages) Analog Devices – High Performance Narrow-Band Transceiver IC

Data Sheet
PACKET STRUCTURE AND CODING
The suggested packet structure to use with the ADF7021 is
shown in Figure 53.
PREAMBLE
SYNC
WORD
ID
FIELD
DATA FIELD
CRC
Figure 53. Typical Format of a Transmit Protocol
Refer to the Receiver Setup section for information on the
required preamble structure and length for the various modulation
schemes.
PROGRAMMING AFTER INITIAL POWER-UP
Table 22 lists the minimum number of writes needed to set up
the ADF7021 in either Tx or Rx mode after CE is brought high.
Additional registers can also be written to tailor the part to a
ADF7021
particular application, such as setting up sync byte detection or
enabling AFC. When going from Tx to Rx or vice versa, the
user needs to toggle the Tx/Rx bit and write only to Register 0
to alter the LO by 100 kHz.
Table 22. Minimum Register Writes Required for Tx/Rx Setup
Mode
Registers
Tx
Reg 1 Reg 3 Reg 0 Reg 2
Rx
Reg 1 Reg 3 Reg 0 Reg 5 Reg 4
Tx to Rx and Rx to Tx Reg 0
The recommended programming sequences for transmit and
receive are shown in Figure 54 and Figure 55, respectively. The
difference in the power-up routine for a TCXO and XTAL
reference is shown in these figures.
Rev. B | Page 41 of 64