I'm writing a little piece of software using direct access to the radio registers in NRF51822. Is NRF51822 capable of calculating BLE checksum in hardware? As far as I'm concerned BLE standard uses x^24 + x^10 + x^9 + x^6 + x^4 + x^3 + x + 1 poly to generate checksum which coresponds to 25-bit binary vector. But NRF_RADIO->CRCPOLY is only 24 bits wide and therefore cannot be used to calculate checksum correctly. Is there any mistake in my interpretation of your reference manual?