Why the CIR_PWR ,in Register file 0x012:04,is always zero?

dear all:
when i read the cir_pwr value ,it is awalys zero,the code is :
cir_pwr =dwt_read16bitoffsetreg(RX_FQUAL_ID,6); why the cir_pwr is awalys zero,when the DW1000(receiver) can get the frame from anyother DW1000(transmister)?

When are you reading it? The value will only be valid after a receive and before you re-enable receive.

This is my code,the CIR_PWR still is zero,please tell me why?

Can try

tmp = dwt_read32bitreg(SYS_CFG_ID)