Frequency independent PCMCIA control signal timing

摘要

A bus interface timing unit responsive to a system clock signal having a frequency that is selectable among a plurality of frequencies. The bus interface timing unit provides timing signals to a bus interface unit that performs functions involving control signals having predetermined timing requirements, such timing requirements being substantially independent of the frequency of the system clock signal. The bus interface timing unit includes a signal generator (20) which is responsive to the system clock signal, and which generates the control signals. These control signals include at least one event signal controlling a time duration in which a predetermined event occurs. Also included is a control unit (10), responsive to a signal representative of the selected frequency of the system clock signal, that controls the signal generator such that the event signal timing is generated in accordance with the predetermined requirements the selected frequencies.