Patent ID: 7808293
Filing Date: 2010-10-05
Classification: G06F,H03H

Abstract:
1. A clock distribution circuit comprising: a clock tree configured to delay a first clock signal supplied from a clock generating unit to a second clock signal; one or more flip-flops configured to operate in accordance with the second clock signal; a combinational circuit connected to the one or more flip-flops, the combination circuit configured to receive a signal output from the one or more flip-flops and generate a clock gating signal; a monitoring circuit including a first delay unit configured to generate an amount of first time delay equal to an amount of time delay by the clock tree and the combinational circuit, and a second delay unit configured to delay an output from the first delay unit by a predetermined amount of second time delay, the monitoring circuit configured to delay a signal taken in by the second clock signal from the clock tree by using the first and second delay units and to predict a timing violation according to whether or not an amount of the first and second time delay produced by the first and second delay units is equal to or greater than a predetermined amount of time; a first logic gate connected to the monitoring circuit and the combinational circuit, the first logic gate configured to fix the clock gating signal to a fixed value and output the signal when the monitoring circuit has predicted presence of the timing violation, and to allow the clock gating signal to pass and be output as-is when the monitoring circuit has predicted absence of the timing violation; and a clock gating circuit connected to the first logic gate and the clock generating unit, the clock gating circuit configured to control supply of the first clock signal from the clock generating unit when the clock gating signal is passed and output as-is from the first logic gate, and to control to stop supply of the first clock signal from the clock generating unit when the fixed value is output from the first logic gate.