how to implement ENCODER MoDE using GPIO ?

[JohnGe]

In my design , MCU controll 8 sets of  STEP MOTOR  .    Every MOTOR  has  A / B Encode pulse outputs
IN CubeMx  Six timers (TIM1-TIM5  & TIM8  )can be configured to ENCODER MODE 。  But  How to implement the other 2 Motors decoder ?   Can we use gpios ?