Data transmission between clock domains for circuits such as microcontrollers

Abstract

A data producer stores input data in a buffer in response to a slow clock signal and provides read data from the buffer in response to a read pointer signal. A data movement circuit reads the input data from the buffer using the read pointer signal and provides an update read pointer signal in response to reading the input data. The data movement circuit operates in response to a fast clock signal, and includes a metastable-free synchronizer circuit having inputs for receiving the update read pointer signal, the slow clock signal, and the read pointer signal, and an output for providing a synchronized read pointer signal equal to the read pointer signal except between a change in the read pointer signal while the slow clock signal is active until an inactivation of the slow clock signal. The buffer provides the read data in response to the synchronized read pointer signal.