Sync signal not output on Novelda X4 SoC

It's not a device I've heard of before.

I'm guessing this is the data sheet you are working from?

Do you have the refclk signal connected from master to the slaves, as it says?

What construction are you using? Some kind of development boards, or have you assembled PCBs?

Thanks for replying.
Yes, that is the datasheet I was referring to, and the refclk (and other clock management setups) is connected as it says.

I'm using a evaluation board X4M03 from Novelda, it consists of a X4 chip, an antenna board, and an Atmel ATSAMS70 MCU on it.

They also provided a firmware library called XeThru Embedded Platform (XEP) which contains the FreeRTOS with the HAL and X4 driver in it, and users are supposed to build the application on top of it. Everything else works fine, but it bothers me that there is a piece of 8051 firmware code (near 2000 bytes) that is programmed into the X4 SoC every time the system starts, but no documents or comments about its functionality, so I am trying to decipher what this code is really doing. Otherwise there is no community or other materials about the Novelda's products so there are not many things I can do.