PSS sweep can't

Hi,

    I am simulating an oscillator with 8-bit trimming ability. An variable "TRIM_CODE" is defined as a decimal value then I use equations to define binary code from D7 to D0, which can be calculated from TRIM_CODE. In test bench, there are 8 vdc, each dc = Di*VDD, Di= D7...D0. 

    I try to sweep TRIM_CODE in PSS sweep, e.g., 97 to 101. However, the final result shows that PSS can not recognize 97 to 101. It only use the default value of TRIM_CODE to run PSS.   

    Any idea about this question ?

BR