SBAA635 Application note

SBAA635 July 2024 AFE7950 , AFE7950-SP , AFE7951 , AFE7953 , AFE7954 , AFE7955

4.2 Jamming Related Latte Functions and Parameters

Configuring the device is in this mode is very simple and can be done by following these steps:

Install Latte Version 2.4.0 or later from TI’s My Secure Resources.
While doing the device bringup, set the following parameters with these values in the bringup script:
```
sysParams.ncoFreqMode              = "FCW"
sysParams.autoFcwConvert    		   = 1
sysParams.txChainDirectCtrl  	        = 1
```
Call the function AFE.txNcoSweep()

AFE. txNcoSweep (en,freqStart1,span1,freqStart2,span2,freqStart3,span3,freqStart4,span4,steps)

With designed for input arguments where:

En= 1 enables jammer mode and 0 brings back the device into default working mode.

freqStart1(MHz)= Start Frequency for Tx channel 1.

Equation 1.

L S B = \frac{F d a c G H z}{2^{32}}

span1(MHz)=Bandwidth for Tx channel 1.

freqStart2(MHz)= Start Frequency for Tx channel 2.

Equation 2.

L S B = \frac{F d a c G H z}{2^{32}}

span2(MHZ)=Bandwidth for Tx channel 2.

freqStart3(MHz)= Start Frequency for Tx channel 3.

Equation 3.

L S B = \frac{F d a c G H z}{2^{32}}

span3(MHz)=Bandwidth for Tx channel 3.

freqStart4(MHz)= Start Frequency for Tx channel 4.

Equation 4.

L S B = \frac{F d a c G H z}{2^{32}}

span4(MHz)=Bandwidth for Tx channel 4.

Steps = Number of frequency steps in which all the Tx channels cam sweep across the designated bandwidths.

The application of the above function is shown with the below example where the AFE7900’s 3 channels are configured to jam three different bands and mentioned:

TX1 is configured to transmit in the 2.4GHz band with BW 85MHz.
TX2 is configured to transmit in the 0.9GHz band with BW 28MHz.
TX3 is configured to transmit in the 5GHz band with BW 125MHZ.

AFE. txNcoSweep (1,2400,85,900,28,5000,125,2400,85,87)

Here the last argument that is, the number of frequency steps is given as 87.