RX231: Noise filter on phase counter MTCLKA, MTCLKB

Hi, 

is there a way to set a noise digital filter on MTCLKA, MTCLKB when I used them as Phase counting signal?

In documentation is written that the width of each signal must be at least 2,5 PCLK, but these means that is a filter or the functionality is not guarenteed?

Thanks MassCard