Patent ID: 7154343
Filing Date: 2006-12-26
Classification: G06F,H03L

Abstract:
1. A semiconductor integrated circuit, comprising an external interface circuit, wherein the external interface circuit includes a clock generation circuit for generating a synchronous clock signal to establish synchronization between data input and output through input and output of a data string sectioned at fixed intervals; wherein the clock generation circuit includes a self-excited oscillator circuit serving as an oscillation source of the synchronous clock signal, and a control circuit for trimming an oscillation frequency of the self-excited oscillator circuit; wherein the control circuit detects sections made at the fixed intervals to the data string, measures a section interval based on an oscillation output of the self-excited oscillator circuit, and controls the oscillation frequency of the self-excited oscillator circuit to match a measurement value to a target value; and wherein the external interface circuit is a USB-compliant interface circuit, and the sections made at the fixed intervals are each designated by an SOF packet that is placed at a frame head.