  The recent established large $\theta_{13}$ in neutrino mixing provides an
optimistic possibility for the investigation of the CP violation, therefore it
is necessary to study the CP-violating phase $\delta_{\rm CP}$ in detail. Based
on the maximal CP violation hypothesis in the original Kobayashi-Maskawa (KM)
scheme of neutrino mixing matrix, i.e., $\delta_{\rm KM}=90^\circ$, we
calculate $\delta_{\rm CK}$ for both quarks and leptons in the Chau-Keung (CK)
scheme of the standard parametrization and find that
$\delta^{\mathrm{quark}}_{\mathrm{CK}}=(68.62^{+0.89}_{-0.81})^\circ$ and
$\delta^{\mathrm{lepton}}_{\mathrm{CK}}=(85.39^{+4.76}_{-1.82})^\circ$,
provided with three mixing angles to be given. We also examine the sensitivity
of $|V_{ij}|$ and $|U_{ij}|$ to $\delta_{\rm CK}$ and $\delta_{\rm KM}$. As a
convention-independent investigation, we discuss the $\Phi$ matrix, which has
elements correspond to angles of the unitarity triangles. We demonstrate the
$\Phi$ matrices for both quark and lepton sectors and discuss the implications
as well as the variations of the $\Phi$ matrix elements with $\delta_{\rm CP}$.
