公开(公告)号：US06226701B1

公开(公告)日：2001-05-01

申请号：US09400738

申请日：1999-09-21

申请人： Peter Chambers ,  Lonnie Goff ,  David R. Evoy ,  Mark Hidson

发明人： Peter Chambers ,  Lonnie Goff ,  David R. Evoy ,  Mark Hidson

IPC分类号： G06F1300

CPC分类号： G06F13/426

摘要： A method and system that enables real-time peripheral devices to be connected to a computer system utilizing Universal Serial Bus architecture. The present invention empowers the computer system to perform an accurate determination of the moment in time a predetermined event occurred within a real-time peripheral device by utilizing the start of frame pulse transmitted from a USB host controller to peripheral devices connected to it. When a predetermined event occurs within a peripheral device, a first timer within the peripheral device starts incrementing to determine the amount of time that elapses until the next start of frame occurs. Once the next start of frame occurs, the first timer stops incrementing and stores the time before start of frame value. Every start of frame pulse causes a second timer located within the USB host controller to start incrementing. The USB host controller interrogates the peripheral device which transfers data to the host controller indicating that (1) an event occurred and (2) the time before start of frame value of the first timer. The USB host controller interrupts the host processor and transfers it the data related to the peripheral device. The processor retrieves the time after start of frame value from the second timer and sums it with the time before start of frame value of the first timer resulting in the time after event value, which is the elapsed time since the predetermined event occurred and the processor read the second timer.

摘要翻译： 一种使实时外围设备能够使用通用串行总线架构连接到计算机系统的方法和系统。 本发明使计算机系统通过利用从USB主机控制器发送到与其连接的外围设备的帧脉冲的开始来准确地确定在实时外围设备中发生的预定事件的时刻。 当在外围设备中发生预定事件时，外围设备内的第一定时器开始递增以确定经过的时间量直到下一帧开始发生。 一旦帧的下一个开始，第一个定时器停止递增并存储帧值开始之前的时间。 每帧帧脉冲启动使位于USB主机控制器内的第二个定时器开始递增。 USB主机控制器询问向主机控制器传送数据的外围设备，指示（1）事件发生，（2）第一定时器的帧值开始之前的时间。 USB主机控制器中断主机处理器并传输与外围设备相关的数据。 处理器从第二定时器检索帧值开始之后的时间，并将其与第一定时器的帧值开始之前的时间相加，导致事件值之后的时间，这是从预定事件发生起经过的时间，处理器 读第二个定时器。