The maximum operating temperature range for the NRF51822-QFAA-R is -40°C to 85°C.
The NFC pins on the NRF51822-QFAA-R can be configured using the NFC peripheral in the Nordic nRF5 SDK. The NFC pins are multiplexed with other functions, so you need to configure the pin multiplexing using the PSEL registers.
The maximum current consumption of the NRF51822-QFAA-R is approximately 14mA in TX mode and 10mA in RX mode, depending on the frequency and transmission power.
Secure boot on the NRF51822-QFAA-R can be implemented using the Nordic nRF5 SDK's secure boot feature, which uses cryptographic algorithms to verify the authenticity of the firmware. You need to generate a secure boot key and store it in the device's flash memory.
The maximum data transfer rate of the NRF51822-QFAA-R is 2Mbps for Bluetooth Low Energy (BLE) and 424kbps for NFC.