We establish a general Kronecker limit formula of arbitrary rank over global function fields with Drinfeld period domains playing the role of upper-half plane. The Drinfeld-Siegel units come up as equal characteristic modular forms replacing the classical ∆. This leads to analytic means of deriving a Colmez-type formula for "stable Taguchi height" of CM Drinfeld modules having arbitrary rank. A Lerch-Type formula for "totally real" function fields is also obtained, with the Heegner cycle on the Bruhat-Tits buildings intervene. Also our limit formula is naturally applied to the special values of both the Rankin-Selberg L-functions and the Godement-Jacquet L-functions associated to automorphic cuspidal representations over global function fields. ∞ .Here Im(z A ) is the "total imaginary part" of z A (cf. the equation (2.5) and (3.3)), and | · | ∞ is the normalized absolute value on C ∞ (cf. Section 2.1). One can (formally) check that E(γ · z A , s; ϕ ∞ ) = E(z A , s; ϕ ∞ ), ∀γ ∈ GL r (k).