Part Number: MSPM0G1106
Hi team,
Customer have questions about how to understand QEI operation at TIMG.
1. QEI (4x / Quadruple Edge) Both edges of PHA (Phase A) and PHB (Phase B) are used for detection. The detection follows the State Machine diagram shown in Figure 27-18. That is, at each edge event, the current state (High/Low) and the previous state (High/Low) are compared to determine whether the edge is a rising or falling edge of Phase A or Phase B. Combined with the state of the other phase, the direction of rotation is determined. Is this understanding correct?
2. QEI (2x / Double Edge) Both edges of PHA (Phase A) are used for detection. Similar to the 4x mode, the detection determines whether the edge is a rising or falling edge of Phase A, and combined with the current state of Phase B, the direction of rotation is determined. Is this understanding correct?
3. QEI (1x / Single Edge) Which edge of Phase A is used for detection? For example, in CCW rotation, a rising edge of Phase A would correspond to a falling edge at the same phase position in CW rotation. Similar to 2x mode, does the hardware internally detect both edges but only count at one specific timing? Or does it always detect the rising edge of Phase A regardless of direction (CW or CCW), resulting in a different detection position depending on direction (as shown in the diagram below)?
Best regards,
Hayashi
