Broadcom Corporation

John Lupienski

Tony Michael Turner

Methods and systems for extending the functionality of an embedded Universal Serial Bus (USB) transceiver interface to handle threshold shift of a USB 2.0 bus during high-speed chirp are presented. A method for a transceiver of a host coupled by a USB 2.0 bus to a device includes receiving a control signal, and selecting one of a first and second zero level voltage threshold according to the control signal. The first threshold is higher than the second to compensate for a shift in a zero level of the bus during high-speed chirp. In one example, the transceiver selects the first threshold when driving a reset signal, and selects the second threshold after detecting a device high-speed chirp signal. In another example, the transceiver selects the second threshold after driving a high-speed chirp sequence. In one example, the control signal includes a signal of a host controller embedded USB transceiver interface.

Method and system for extending the functionality of an embedded USB transceiver interface to handle threshold shift of a USB 2.0 bus during high-speed chirp

A multi-bit write pointer that is associated with a first clock can be converted to a single-bit write pointer. A multi-bit read pointer that is associated with a second clock can be converted to a single-bit read pointer. The first clock and the second clock are not synchronized. One or more guard bits can be associated with the single-bit write pointer and/or the single-bit read pointer. The single-bit write pointer and the single-bit read pointer can be compared. According to an embodiment, an error can be detected in response to comparing the single-bit write pointer and the single-bit read pointer.

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Phoenix, AZ, United States of America

John Lupienski