5.8 Multiple Gain Table

There are restrictions regarding the maximum transmit power of a wireless device according to the regulatory agencies of the region. For Wi-Fi devices, the maximum transmit power is limited according the regulation of the region in which the Wi-Fi device is used. The gain table can be used to configure the transmission power in WINC. The digital gain (DG) that are used for different channels and different data rates are stored in ATWINC15x0 Flash as a table called Gain table. In ATWINC15x0, the Power Amplifier (PA) and Pre-power Amplifier (PPA) values are configured in the firmware directly.

The following figure shows the format of the gain table.

The Gain tables are provided as part of firmware update package in form of .csv file available at src/firmware/Tools/gain_builder/gain_sheets folder. The gain values are downloaded as part of complete download process. For more details, see "WINC Devices – Integrated Serial Flash Memory Download Procedure" document.

Prior to v19.6.1 only one gain table was supported in ATWINC15x0, with which the WINC can only operate in one regulatory region without requiring different Flash content.

The ATWINC15x0 firmware version 19.6.1 or above supports multiple gain table and the Flash can store up to four gain tables. The table can be selected by the Host MCU using the API m2m_wifi_set_gain_table_idx. If the ATWINC15x0 has to operate in multiple region with maximum transmit power allowed in that region, multiple gain table feature can be used to select gain table (by Host MCU) based on the region in which the ATWINC15x0 is operated.