Patent ID: 6012115
Filing Date: 2000-01-04
Classification: G06F

Abstract:
In a computer system having a processor coupled to a bus, a computer readable memory unit coupled to said bus, a Universal Serial Bus (USB) host controller generating start of frame pulses and coupled to said bus, and a peripheral device coupled to said USB host controller, a method for temporally determining a real-time event within said peripheral device comprising the steps of:a) responsive to an event occurring within said peripheral device, initiating a first timer counting until a next start of frame pulse is detected and holding the count of said first timer;b) responsive to said next start of frame pulse, initiating counting of a second timer;c) after said next start of frame pulse, said USB host controller interrogating said peripheral device to determine whether an event occurred within said peripheral device;d) provided an event is determined at step c), obtaining said count of said first timer and reading a current count of said second timer;e) summing said counts of said first timer and said second timer to determine a third count value, said third count value representing a period of time from said event occurring to a time at which said second timer was read; andf) recording said third count value into said computer readable memory unit.