How to set cc2538 + cc2592 tx power 0

Other Parts Discussed in Thread: CC2592, CC2538

Hi All

I know using this function "macRadioSetTxPower()" to set tx power.

CC2592 Spec:7.5dBm ~ 22dBm => 0x42 ~ 0xFF

But the spec doesn't define the value of tx power 0.

How can I set tx power 0?

Sometimes I need to turn off  tx power.

Thanks a lot.