Hi Fathima,
Testing is very easy. Just generate a FIRE signal (TX_EN). For medical ultrasound applications the pulse repetition frequency should be calculated as follows: PRF=V/(2*S)
V=1560m/s (mean acoustic wave velocity in the human body)
S - penetration depth (practically 2-24cm)
For beamformer testing purposes you can use just only 2 voltages 1.8V and 3.3V.
Good luck,
Mariusz