PBKDF2 when dkLen and hLen have the same size I was reading RFC 2898 and something is not clear to me. When I use PBKDF2 with SHA-256 and I want a derived key with length 32 bytes (the same length as my hash function output), your derived key only exists out 1 block (l = 1) of size hLen = 32 bytes. 

This seems trivially, but i want to be very sure! Is this correct?
The output length of the F step of PBKDF, i.e. the T_i each are of the size of your hash function's (or actually: your PRF's) output.

So yes, when the desired output size is as large (or smaller) as the hash function output, we have l = 1 and thus only one call to F(P, S, c, 1).

I suppose this is also the most common way to use PBKDF-2, the extension to longer generated key sizes is only included to make the scheme more generally usable.