Permissive Changes against Full Retest after a Firmware Update
Firmware updates altering output power, channels, or DFS logic trigger mandatory permissive change filings or retests before distribution.
Power Table Registers
Meaning
Memory locations in a wireless transceiver that store output power settings across supported channels and modulation modes define a hardware configuration interface. In Wi-Fi and Bluetooth system-on-chip architectures, power table registers map regulatory power limits to physical power amplifier control states. The boundary of these registers covers internal RAM or non-volatile memory allocated for RF front-end gain control.
Gain Mapping
Baseband firmware reads power table registers during channel initialization to set internal digital-to-analog converter levels and external amplifier gain stages. In operational radio modules, power table registers store signed attenuation values for individual frequency channels to offset antenna gain variations across frequency bands. Regulatory compliance firmware restricts writing to these registers, preventing end-user applications from exceeding country-specific power limits.
Thermal throttling routines dynamically decrement values stored inside gain registers during prolonged high-duty-cycle transmissions to maintain die temperatures within safe limits. System integrators calibrate register settings during factory RF testing to compensate for manufacturing variations in power amplifier output.
Regulatory Masking
Software drivers load regional power limit tables into non-volatile memory based on geographic location data from cellular towers or GPS receivers. Dynamic register loading allows a single hardware assembly to operate legally across North American, European and Asian spectrum regulations. Engineering verification teams inspect memory dumps to ensure lock bits prevent register tampering after boot completion.
Calibration Log
Factory production equipment writes calibrated output power offsets directly into non-volatile power table registers during end-of-line RF testing. Calibration parameter files document target power levels against actual measured RF output for audit tracking.