Method of controlling read address, physical information acquisition apparatus, and semiconductor device

Abstract

To reduce random noise caused by address setting in an apparatus that controls a read address of an image sensing device, without causing a significant increase in circuit complexity. A ring shift register sets a low-order address value depending on a value in steps of which an overall address value is incremented, and a Gray code counter sets a high-order address value. In the ring shift register, a carry from the lowest-order bit to the highest-order bit does not occur, and thus use of the ring shift register makes it possible to reduce the maximum number of toggled bits. The Gray code counter does not need to include a complicated circuit for switching the value in steps of which to increment the high-order address value. Thus, an overall address setting unit can be configured in a simple form without needing any complicated circuit such that addressing can be performed while maintaining the number of toggled bits within a small range and thus random noise generated in the addressing operation can be minimized.