Data interface with variable bit clock for changing the number of time slots in a frame

摘要

The present invention relates to methods and apparatus for data transfer. A data interface is described with at least a first data terminal for either outputting or receiving a data signal. In bi-directional embodiments there may be one terminal for receiving data and one terminal for outputting data. A bit clock terminal outputs or receives a bit clock signal; and a frame clock terminal for outputs or receives a frame clock signal. Interface control circuitry is configurable to associate data outputted or received in each frame with time slots (1-8) of a predetermined number of bits (x, y, z) wherein the control circuitry is adapted such that the frequency of the bit clock signal can be changed at any time so as to vary the number of time slots in a frame.

主权项

1. A data interface apparatus comprising:
a first data terminal for outputting or receiving a data signal; a bit clock terminal for outputting or receiving a bit clock signal; a frame clock terminal for outputting or receiving a frame clock signal; and control circuitry configured to associate data outputted or received in each frame with time slots of a predetermined number of bits; wherein the control circuitry is configured to vary the frequency of the bit clock signal at any time when the data interface apparatus is outputting or receiving said data signal so as to vary the number of time slots in a frame; and wherein the control circuitry is configured to associate predetermined time slots with predetermined data channels and to access a data channel only if the frame contains an associated time slot.