SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
Position counter data may be captured in different manners. In some systems, the position counter is accumulated continuously for multiple revolutions and the position counter value provides the position information with respect to the known reference. An example of this is the quadrature encoder mounted on the motor controlling the print head in the printer. Here the position counter is reset by moving the print head to the home position and then position counter provides absolute position information with respect to home position.
In other systems, the position counter is reset on every revolution using index pulse and position counter provides rotor angle with respect to index pulse position.
Position counter can be configured to operate in following four modes
In all the above operating modes, position counter is reset to 0 on overflow and to QPOSMAX bifield value in EQEP_QPOSMAX register on underflow. Overflow occurs when the position counter counts up after QPOSMAX value. Underflow occurs when position counter counts down after "0". Interrupt flag is set to indicate overflow/underflow in EQEP_QINT_EN_FLG register.