The present disclosure relates generally to power management in electronic circuits, and more particularly to a method and an apparatus for reducing power consumption in an electronic system communicating over a serial bus.
The Inter Integrated Circuit (I2C) bus is a well known bi-directional, two-wire serial data bus that may be used to enable one or more devices, including integrated circuit (IC) chips, to communicate with one another and form an electronic system. Each device coupled to the I2C bus is recognized by a unique address and may operate either as a receiver or transmitter of information. Additionally, these devices are configurable to operate in either a master or slave mode, depending on whether the device initiates communication with other devices or simply receives communication from other devices.
The I2C bus includes a serial data line for communicating data and a serial clock line for communicating a clock signal. Transfer of data between one or more master devices and the one or more slave devices occurs in an asynchronous manner and in accordance with the I2C bus communications protocol. A slave device coupled to the I2C bus may be configured to operate in a synchronous domain.
It would be desirable to turn off one or more components included in the slave device to conserve power, the slave device being operable in the synchronous domain. However, by placing the slave device or components thereof in a power off mode there is an increased probability that some I2C transactions (such as performing a write to the slave device) may be missed by the slave device. If the slave device is always operated in a power on state to capture the I2C transactions then the power consumption is increased. Therefore, a need exists to provide an improved method and apparatus to reduce power in the slave device while being responsive to capturing I2C transactions.