位置基准生成 不太明白，大神能讲解一下吗？

请您看一下www.ti.com/.../sprabz0.pdf 的33页

The refPosGen() module basically cycles the position reference through a set of values as defined in an array ‘posArray’. These values represent the number of the rotations/ turns with respect to the initial alignment position. Once a certain position value as defined in the array is reached, it will pause for a while before slewing towards the next one. Therefore, these array values can be referred as parking positions. During transition from one parking position to the next, the rate of transition (or speed) is set by ‘posSlewRate’. The number of positions in ‘posArray’ to pass through before restarting from the first value is decided by ‘ptrMax’. Hence, add the variables “posArray”, “ptrMax” and “posSlewRate” to the expressions window.