Mario, what do you mean by PSP? Wikipedia gives 7 meanings for PSP in an IT context, plus Play Station Portable which is an I product.
I suspect you mean ‘Personal Software Process’. If so, I strongly recommend that you do not try to measure the productivity of individuals, using a software size measure (COSMIC, IFPUG or SLOC) to measure their work-output. Software development is a team process requiring multiple skills. In the early days of using Function Points, a North American bank even tried to pay its IT staff on the basis of measuring their share of FP delivered. It was a disastrous failure.
Hello Mario, as you should know, PSP (Personals Sw Proc.) needs to measure size and effort to project estimations based on your personal behavior.
Effort is measured in Time spent on each task you did.
Size is generally shown as LOC (Lines of Code), but this is not mandatory, you can simply susbstitute LOC any size unit you can came over.
CFP (COSMIC Function Points) are another way to measure size and as such you can use it with PSP without problem.
Remember that the estimation of your development is made by your past performance so you should create your own Relative Size Table using Std Dev.
In fact, when I took the PSP Certified Programmer Course, while some of us worked with Java, C# and traditional languajes, some guys changed LOCs by the number of writes, reads and transformation they needed to use, wich btw is in part what COSMIC uses to determine size.