  The ratio $\Delta m_K/m_K$ within the standard model with 3 generations is
calculated as a function of the CP nonconserving phase $\delta_{13}$ and the
quark masses $m_c,m_t$ assuming the current values of the
Cabibbo-Kobayashi-Maskawa mixing angles. We have found that varying
$\delta_{13}$ and $m_c$ within the allowed range, not all the values for the
top quark mass fit the experimental value for that ratio.
