USB integrated bidirectional digital isolator channel across an interface between two USB devices

• US 7,899,968 B2
• Filed: 07/26/2007
• Issued: 03/01/2011
• Est. Priority Date: 07/26/2007
• Status: Active Grant

• Current Assignee: Kinetic Technologies International Holdings LP
• Original Assignee: Akros Silicon, Inc. (Kinetic Technologies Incorporated)
• Inventors: Bliss, David, Ghoshal, Sajol
• Primary Examiner(s): PEYTON, TAMMARA R
• Application Number:
  US11/881,281
• Publication Number:
  US 20090031056A1
• Time in Patent Office: 1,314 Days
• Field of Search: 710 31- 33, 710/59, 710/305, 710/110, 710/36
• US Class Current: 710/305
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence

Abstract

An interface between USB devices employs isolation techniques to provide electrical isolation of a USB signal for transmission of the USB signal between the devices. Unidirectional isolator channels are utilized to transmit the USB signals, and a selection of an isolator channel operating in an intended direction is performed by either direction control logic or a USB hub function. Logic may be employed to detect a device attempting to initiate a USB signal. The logic operates to enable a transmitter on a receiving side and isolate the USB signal through an isolator channel operating in a transmission direction.

Claims

1. A method of communicating and isolating a digital signal across an interface between two devices, the method comprising:

receiving the digital signal at the interface;

analyzing the digital signal at the interface to detect an initiation for a transmission of the digital signal from a transmitting device to a receiving device to determine an intended direction of the digital signal;

transmitting the digital signal to an isolator channel configured to isolate the digital signal in the intended direction of the digital signal by monitoring the digital signal for a transition from an idle state to a non-idle state;

isolating the digital signal at the isolator channel;

enabling a receiving device transceiver for receiving the digital signal; and

transmitting the isolated digital signal in the intended direction of the digital signal to the receiving device via the receiving device transceiver.

2. The method of claim 1, further comprising:

analyzing the digital signal at the interface to detect a completion of the transmission of the digital signal; and

disabling the receiving device transceiver.

3. The method of claim 2, wherein analyzing the digital signal at the interface to detect a completion of the transmission of the digital signal comprises monitoring the digital signal for a transition from a non-idle state to an idle state.

4. The method of claim 2, wherein disabling the receiving device transceiver comprises disabling the receiving device transceiver after a predetermined number of cycles elapse after the detection of the completion of the transmission of the digital signal.

5. The method of claim 1, wherein one of the two devices is a USB host, and wherein the second of the two devices is a USB device.

6. One or more integrated circuit devices having a process embodied in said integrated circuit device, said process performing a method of isolating a digital signal across a USB interface between two USB devices, the method comprising:

receiving the digital signal at the interface;

analyzing the digital signal at the interface to detect an initiation for a transmission of the digital signal from a transmitting device to a receiving device by monitoring the digital signal for a transition from an idle state to a non-idle state;

determining a transmission direction of the digital signal based upon the analysis and the detection of the initiation for the transmission;

transmitting the digital signal to an isolator channel configured to isolate the digital signal in the determined transmission direction;

isolating the digital signal at the isolator channel;

enabling a receiving device transceiver for receiving the digital signal; and

transmitting the isolated digital signal in the determined transmission direction to the receiving device via the receiving device transceiver.

7. The one or more integrated circuit device of claim 6, wherein said process performs the further method of:

disabling the receiving device transceiver upon completion of the transmission of the digital signal.

8. The one or more integrated circuit device of claim 7, wherein said process performs the further method of:

detecting completion of the transmission of the digital signal by monitoring the digital signal for a transition from a non-idle state to an idle state.