US 8,412,873 B2Granted

USB bridge

AssigneesGemalto SA, Invia

InventorsRobert Leydier, Alain Pomet, Benjamin Duval

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Abstract

A bridge circuit 10 is provided between first data port A1, A2 and second data port B1, B2. The bridge circuit comprises a first transceiver stage 40 comprising at least one input buffer 11, 14 and at least one tri-state output buffer 12, 13 linked to the first data port, a second transceiver stage 50 comprising at least one input buffer 21, 24 and at least one tri-state output buffer 12, 13 linked to the second data port, a first detection circuit 31 for detecting the arrival of a packet by the first data port, a second detection circuit 37 for detecting the arrival of a packet by the second data port. A selection circuitry 34, 35 enables the output of tri-state output buffer of the first or of the second transceiver stage depending of the detection made by the first and second detection circuits.

Claims5

Dependent claims

A bridge circuit between a first data port and a second data port, said bridge circuit comprising:

a first transceiver stage supplied within a first voltage range, said first transceiver stage comprising at least one input buffer having an input linked to the first data port and at least one tri-state output buffer having an output linked to the first data port,
a second transceiver stage supplied within a second voltage range, said second transceiver stage comprising at least one input buffer having an input linked to the second data port and at least one tri-state output buffer having an output linked to the second data port,
a first detection circuit linked to first transceiver stage for detecting the arrival of a packet by the first data port,
a second detection circuit linked to second transceiver stage for detecting the arrival of a packet by the second data port,
a selection circuitry for enabling the output of the tri-state output buffer of the first or of the second transceiver stage depending of the detection made by the first and second detection circuits,
a set of pull-up resistors connected to the first data port, said set of pull-up resistors being connected to the first voltage range as a function of the value of the first voltage range,
a first set of pull-down resistors connected to the first data port, said first set of pull-down resistors being connected to a ground as a function of the value of the first voltage range,
a second set of pull-down resistors connected to the second data port, said second set of pull-down resistors being connected to the ground as a function of the value of the second voltage range.

5 more elements

Dependencies are inferred from the claim text.