How to get CIR Power value from register?

at dwm1000,
there is cleary documented about this topic, i can get the CIR Power value from register

but move to dwm3000 (or dw3000)
it is not documented at all, i think. i can see CIR Accumulator memory but nothing about CIR Power value

dw3000 user manual section 4.7.2, there is RX fomular, how can i get C value ?? (which is CIR Power value)

i have tried following code.



but no chance to get the value. it was always zero.

did i missing something ??