I designed a motherboard and had to add hardware to make the keyboard controller reset work. The problem was that was that the reset pulse from the keyboard controller was on only 6uS wide, whereas most modern chipsets have denounce circuitry (filters) on their reset pins to make sure noise on the line doesn't trigger reset. The denounce circuitry on the chipset of the board I designed ignored anything less than 14mS. Therefore I added an edge-detector/pulse-stretcher.
It sure would be nice if industry would recognize the need for a standard here.