The 5P49V5901 is a programmable clock generator intended for high performance consumer, networking, industrial, computing, and data-communications applications. Configurations may be stored in on-chip One-Time Programmable (OTP) memory or changed using I2C interface. This is IDTs fifth generation of programmable clock technology (VersaClock® 5). The frequencies are generated from a single reference clock. The reference clock can come from one of the two redundant clock inputs. A glitch less manual switchover function allows one of the redundant clocks to be selected during normal operation. Two select pins allow up to 4 different configurations to be programmed and accessible using processor GPIOs or bootstrapping. The different selections may be used for different operating modes (full function, partial function, partial power-down), regional standards (US, Japan, Europe) or system production margin testing. The device may be configured to use one of two I2C addresses to allow multiple devices to be used in a system.