  A simple model to describe the energetic phase diagram of electron-doped
cuprate superconductor is developed. Interband pairing operates between the UHB
and the defect states created by doping and supplied by both extincting HB-s.
Two defect subbands correspond to the ($\pi, 0$) and ($\pi /2,\pi /2$) momentum
regions. Extended doping quenches the bare normal state gaps (pseudogaps).
Maximal transition temperature corresponds to overlapping bands ensemble
intersected by the chemical potential. Illustrative results for $T_c$, pseudo-
and superconducting gaps are calculated on the whole doping scale. Major
characteristics features on the phase diagram are reproduced. Anticipated
manifestation of gaps doping dynamics is discussed.
