  We use a 100 ks long XMM-Newton observation of the Narrow-Line Seyfert 1
galaxy Ark 564 and combine it with the month-long monitoring of the same source
produced by ASCA, to calculate the phase lags and coherence between different
energy bands, over frequencies ~ 10^{-6} to 10^{-3} Hz. This is the widest
frequency range for which these spectral-timing properties have been calculated
accurately for any AGN. The 0.7-2 and 2--0 keV ASCA light curves, and the
XMM-Newton light curves in corresponding energy bands, are highly coherent (~
0.9) over most of the frequency range studied. We observe time lags between the
energy bands, increasing both with time-scale and with energy separation of the
bands. The time lag spectrum shows a broad peak in the 10^{-5} - 5x10^{-4} Hz
frequency range, where the time lags follow a power law slope ~ -0.7. Above ~ 5
x 10^{-4} Hz the lags drop below this relation significantly. This change in
slope resembles the shape of the lag spectra of black hole X-ray binaries
(BHXRB) in the very high or intermediate state. The lags increase linearly with
the logarithm of the separation of the energy bands, which poses one more
similarity between this AGN and BHXRBs.
