Code CAP calculation from Cap DATA

Hello !

I work on the AD7745/4AD77466 evaluation board. The software application from AD displays code CAP which represents the value of the capacitance in hexadecimal.
I work with the single ended mode with no CAPDAC in first step. We will add a CAPDAC value in a second step.

I develop my own application where I read the CAP DATA registers to have the raw data.
This raw data are different from Code CAP of the AD software application.

I read all the datasheets on the AD7746 and his evaluation board datasheet too, but I can't find the right formula.

1) What is the formula to have the Code CAP from the raw data(CAP DATA registers) ?

2) I already have the formula for convert the value in hexadecimal in pF. So that is not my question.

Please help me I can't find any respond on it and I don't know why. 
I must have done something.