Patent ID: 7418605
Filing Date: 2008-08-26
Classification: H01L

Abstract:
1. An integrated circuit, comprising: first and second functional circuit blocks; and first, second, and third power supply rails, wherein the first and second power supply rails are upper supply rails and the third power supply rail is a lower power supply rail, wherein the first functional circuit block is electrically coupled to the first power supply rail, the second functional circuit block is electrically coupled to the second power supply rail, and the third power supply rail is electrically coupled to at least one of the first and second functional circuit blocks, wherein the second power supply rail is switchably coupled to a source of operating potential, wherein the first functional block comprises sequential logic circuitry and the second functional circuit block comprises combinational logic circuitry, and wherein a first source of operating potential is coupled to the first functional block and a second source of operating potential is coupled to the first and second functional blocks in an active operational state.