Adaptive isochronous USB audio to RF communication device

摘要

A method of and a system for synchronizing isochronous audio data frames provided by a USB interface to a clock of a wireless RF communication device is provided. The USB interface and the wireless RF communication device are connected via an I2S link, the method comprising receiving the isochronous audio data frames and the wireless RF communication device clock in a streaming controller, phase locking the isochronous audio data frames to a USB interface clock, counting start-of-frame pulses of the phase locked isochronous audio data frames, comparing the counted start-of-frame pulses with the wireless RF communication device clock to determine a difference signal, the difference signal triggering a synchronization event code when a threshold difference has been reached, rate matching the isochronous audio data frames to the wireless RF communication device clock upon receiving the synchronization event code.

主权项

1. A method of synchronizing isochronous audio data frames while avoiding a delay caused by interruption of the audio stream, and re-acting on of a two-way low latency voice telephonic audio stream provided by an interface to a clock of a wireless RF communication device, the interface and the wireless communication device being connected via an audio link, the method comprising:
receiving the isochronous voice audio data frames and the wireless communication device clock, synchronizing a data rate of the isochronous audio data frames to an interface clock, counting start-of-frame pulses of the synchronized isochronous audio data frames, establishing a predetermined threshold of differences between the clock and start of frame pulses; comparing the counted start-of-frame pulses with the wireless communication device clock to determine a difference signal, the difference signal triggering a synchronization event code when said predetermined threshold difference has been reached, rate matching the isochronous audio data frames to the wireless communication device clock upon receiving the synchronization event code wherein, if the start of frame pluses are lagging the wireless clock, samples are inserted into the audio stream, and wherein, if the start of frame pluses are leading the wireless clock, samples are removed from the audio stream.