Analog Devices ADRV9001 User Manual page 123

Reference Manual ADRV9001
FREQUENCY HOPPING
continuously toggled. After the pulse train of transmitter setup stops (meaning a hop edge without a preceding transmitter setup rising edge),
the transmitter channel is powered down at the next hop edge. A subsequent transmitter setup begins the process again.
This example shows a four-frame delay, with the transmitter frame starting on air at the fifth frame after the first transmitter setup rising edge.
To account for the transition period between the consecutive frames, pad the valid data with guard symbols. These are marked by the gray
boxes, as shown in Figure 119. Also, pad the data to keep the transition and dwell times consistent. This is because the transition required for
the first transmitter frame is greater than for consecutive frames.
There is also the option to program the "riseToAnalogOn" timing parameter to 0, indicating the analog power-up can be powered up
immediately after the hop edge. Then, time the data to the antenna based on when the transmitter setup rising edge is dropped and start
transmitting data.
For the PLL Mux mode, the transmitter setup falling edge marks the beginning of the interface. "txAnalogPowerOnFrameDelay" starts to
decrease from the original value when the hop signal first samples a high of the transmitter setup signal until it is decreased to 0. When
reaching 0, it waits another frame before the transmitter analog is powered on due to the 1 frame delay in the PLL Mux mode. The value
remains 0 until the transmitter setup is sampled with low, and the value then sets back to the original value.
Figure 119. Tx Only with Long Propagation Delay for PLL Mux Mode
For the PLL Retune mode, the difference is the transmitter setup rising edge, which now marks the beginning of the interface. "txAnalogPower-
OnFrameDelay" starts to decrease when the hop signal first samples a High of transmitter setup signal, until it is decreased to 0. When
reaching 0, the transmitter analog is powered on as there is no 1 frame delay in the PLL Retune mode. The value remains 0 until the transmitter
is sampled with low, and the value is then set back to the original value.
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