Low-Power Optimization Techniques#

M4 Low-Power Optimization#

  • Based on the SRAM requirements for NWP, memory configured for M4 can be increased as much as possible, and only the required size of RAM banks can be retained during sleep.

    • Example:

      • Scenario 1: RAM memory configuration of 480 kB for NWP, and 192 kB for M4 with entire RAM retention

      • Scenario 2: RAM memory configuration of 352 kB for NWP, and 320 kB for M4 with 192 kB RAM retention

  • Using Power Manager Tickless functionality would configure M4 into Sleep whenever the system is IDLE, resulting in reduced average current consumption.

NWP Low-Power Optimization#

  • Enabling SL_SI91X_EXT_FEAT_LOW_POWER_MODE: BIT(19) in Extended Custom Feature Bitmap in the boot configuration, helps in reducing average current consumption during NWP Associated Sleep.

  • Make a smart configuration of WLAN Keep-Alive, TCP Keep-Alive, and MQTT Keep-Alive parameters as per your application to reduce the current consumption.

  • If broadcast/multicast data is not important for your application, further power consumption can be reduced using the broadcastfilter() API.

  • Quick scan and Quick join features:

    • Quick Scan feature allows the device to scan for a particular access point on a specific channel, which helps reduce scanning time and lower current consumption.

    • Quick join feature enables the device to send authentication and association frames without unicast probe requests, which helps reduce connection time and lower current consumption.

  • The dwell time of the scan in each channel can be configured using sl_si91x_configure_timeout() API, as needed to reduce current consumption further.