Modes Of Operation - Analog Devices ADRV9001 User Manual

Preliminary Technical Data
HOP signal marks the beginning and the end of a Transmit or a Receive frame. The HOP signal is triggered by a DGPIO pin, which can
be assigned from any of the available DGPIO pins. Each edge of the HOP signal marks both the possible start and end of a hop frame.
Channel Setup Signal
The channel enable pins (namely Tx/Rx_ENABLE pins), used in non-FH operation, are repurposed in frequency hopping to signal if an
upcoming HOP frame is operating on an Rx or Tx channel. These pins are redefined as Rx/Tx setup; however, they are the same
dedicated channel enable hardware pins, which are used to enable an Rx or Tx channel in non-frequency hopping mode.
As seen in Figure 103, this is the LO muxing mode, the channel setup is used to signal a channel is enabled one frame in advance. For
example, the channel setup signal is high prior to the start of Hop Frame 0, but that channel is not enabled until Hop Frame 1.
For LO retune mode, we still use the HOP signal to sample Tx/Rx setup signal. However the RF channel is enabled in HOP frame 0
instead of HOP frame 1, shown in Figure 104.
The frequency information comes from the BBIC. Before each Tx or Rx setup, ADRV9001 expects to get some message (this may come in
various forms which is discussed in later sections) which indicates a frequency. Prior to each hop, the channel (Tx or Rx) information and
the frequency information are obtained.
Note Tx setup signal has special meaning. In LO muxing mode, Tx setup falling edge indicates the start of the interface. In LO retune
mode, Tx setup rising edge indicates the start of the interface. More information will be shown in details.

MODES OF OPERATION

ADRV9001 allows the user to achieve various framing requirements by providing three modes of operation.
Table 36. Frequency Hopping Modes of Operation
Mode Transition Time
LO mux with hop table < channel setup
preprocess + lo retune
LO mux with hop table < channel setup
real time update + lo retune
LO retune with hop > channel setup
table real time update + lo retune
Currently, all modes of frequency hopping operation within ADRV9001 use a fast PLL calibration. The modes are differentiated by the
user's transition time and dwell time requirements. ADRV9001 defines two modes of PLL usage: LO Muxing and LO Retune.
Note there are two modes of PLL calibration, one is fast one is normal. In terms of phase noise, there is no difference between the fast and
normal modes. Normal mode tracks temperature over time where fast mode does not. Therefore fast mode takes less time. For frequency
HOP SIGNAL
CHANNEL SETUP
Figure 103 Channel Setup Signal for LO Muxing
Figure 104 Channel Setup Signal for LO Retune
Total frame duration
(transition + dwell)
> 13 us
> 25 us
> max(25 us,
LO_retune_time)
Rev. PrC | Page 105 of 338
CHANNEL RF
ENABLED
HOP FRAME 0 HOP FRAME 1
PLL Return
PLLs Time
2 LOs 2 transitions + 1
dwell
2 LOs 1 transitions +
sub 1 dwell
1 LO Sub 1 transitions
UG-1828
PLL Cal
Mode Channel
Fast Cal Single (1T1R)
mode
Fast Cal Single/Dual (1T1R or
mode 2T2R diversity)
Fast Cal Single/Dual (1T1R or
mode 2T2R diversity)