22.3.2.2 Reading a Sensor Value

Once all the settings are configured, values from the sensor can be read. The simplest way to read a value is to turn on the BiSS module, set the AGS bit and read from the B1SCDATAxX register. This is the minimum required to read a value, however, the following additional steps are highly recommended:

  1. After configuring all settings, turn on the BISS module using the ON bit. This is also a good time to monitor the SLx Status bit. The SLx bit quickly checks the status of the SL line to determine if the client is pulling the line high, which is required for successful BiSS transmission.
    Note: Monitoring the SLx status bit is used to determine if the client is powered on and connected.
  2. Initialize the BiSS module using the INIT bit. Initialization has two useful purposes: when the INIT bit is set, the status information is reset to provide assurance that the BiSS module starts off without any erroneous errors. Initialization also sends two pulses that allow the BiSS engine to determine the line delay introduced on MA. This value can immediately be read in the B1SCDATA0L register.
  3. After the BiSS module is initialized, poll INSTRWA. It is critical to operations that the instructions are not written to while still in progress. Then the AGS bit can be set to start triggering the getsense to allow the user to read the B1SCDATAxX registers for the sensor values.