Can two TPS84210RKG chips operate synchronously?

Hello!
I am going to use the TPS84210 chips for C6424 DSP powering.
1.2V for core and 1.8V for DDR memory.
The chip have RT/CLK pin for external clock.
I do not understand what I can use as a clock source.
I thought about the PH PIN, but the documentation is clearly written: "Phase switch node. These pins should be connected by a small copper island under the device for thermal PH relief. Do not connect any external component to this pin or tie it to a pin of another function."
Can these two chips operate synchronously?
Serg.