  We have developed a generalized electronic phase separation model of
high-temperature cuprate superconductors that links the two distinct energy
scales of the superconducting (SC) and pseudogap (PG) phases via a
charge-density-wave (CDW) state. We show that simulated electronic-density
modulations resembling the charge order (CO) modulations detected in cuprates
intertwine the SC and charge orders by localizing charge and providing the
energy scale for a spatially periodic SC attractive potential. Bulk
superconductivity is achieved with the inclusion of Josephson coupling between
nanoscale domains of intertwined fluctuating CDW and SC orders, and local SC
phase fluctuations give rise to the Fermi arcs along the nodal directions of
the SC gap. We demonstrate the validity of the model by reproducing the
hole-doping dependence of the PG onset temperature $T^*$, and the SC transition
temperature $T_c$ of ${\rm YBa_2Cu_3O_y}$ and ${\rm
Bi_{2-y}Pb_ySr_{2-z}La_zCuO_{6+\delta}}$. The results show that the periodicity
of the CDW order is controlled by the PG energy scale, and the hole-doping
dependence of the SC energy gap is controlled by the charge ordering free
energy.
