TMS320F28375S: What is the result if the input of CLAcosPU() is out of [-1,1]?

Yuzheng Chen said:

1. What if the input parameter is out of the range [-1 1]?

The function has been written with this constraint.  Values outside of this range  may not produce the desired result. 

Yuzheng Chen said:

2. How DSP select the values of K and X?

If you look at the assembly source code for the function, the comments explain where the values K and X are stored in tables used by the function

; MR3 = K = integer(radPU*TABLE_SIZE*Pi/(2*Pi))
; MR3 = K & TABLE_MASK
; MR3 = K * 2
; MAR0 = address of Sin(K)
; MR1 = frac(TABLE_SIZE*radPU*Pi/2*Pi)
; MR0 = 2*Pi/TABLE_SIZE
; MR1 = X = frac(TABLE_SIZE*radPU*Pi/2*Pi) * (2*Pi/TABLE_SIZE)
; MR0 = Coef3_neg

Regards

Lori