Hi-Speed USB Device PHY with UTMI Interface

Datasheet

7.6USB 2.0 Transceiver

The SMSC Hi-Speed USB 2.0 Transceiver consists of the High Speed and Full Speed Transceivers, and the Termination resistors.

7.6.1High Speed and Full Speed Transceivers

The USB3280 transceiver meets all requirements in the USB 2.0 specification.

The receivers connect directly to the USB cable. This block contains a separate differential receiver for HS and FS mode. Depending on the mode, the selected receiver provides the serial data stream through the multiplexer to the RX Logic block. The FS mode section of the FS/HS RX block also consists of a single-ended receiver on each of the data lines to determine the correct FS linestate. For HS mode support, the FS/HS RX block contains a squelch circuit to insure that noise is never interpreted as data.

The transmitters connect directly to the USB cable. The block contains a separate differential FS and HS transmitter which receive encoded, bit stuffed, serialized data from the TX Logic block and transmit it on the USB cable.

7.6.2Termination Resistors

The USB3280 transceiver fully integrates all of the USB termination resistors. The USB3280 includes the 1.5kΩ pull-up resistor on DP. In addition the 45Ω high speed termination resistors are also integrated. These integrated resistors require no tuning or trimming. The state of the resistors is determined by the operating mode of the PHY. The possible valid resistor combinations are shown in Table 7.1.

„RPU_DP_EN activates the 1.5kΩ DP pull-up resistor

„HSTERM_EN activates the 45Ω DP and DM high speed termination resistors

Table 7.1 DP/DM Termination vs. Signaling Mode

 

 

 

 

RESISTOR

 

UTMI+ INTERFACE SETTINGS

SETTINGS

 

 

 

 

 

 

SIGNALING MODE

XCVRSELECT

TERMSELECT

OPMODE[1:0]

RPU_DP_EN

HSTERM_EN

 

 

 

 

 

 

Tri-State Drivers

Xb

Xb

01b

0b

0b

 

 

 

 

 

 

Power-up

1b

0b

00b

0b

0b

 

 

 

 

 

 

Peripheral Chirp

0b

1b

10b

1b

0b

 

 

 

 

 

 

Peripheral HS

0b

0b

00b

0b

1b

 

 

 

 

 

 

Peripheral FS

1b

1b

00b

1b

0b

 

 

 

 

 

 

Peripheral HS/FS Suspend

1b

1b

00b

1b

0b

 

 

 

 

 

 

Peripheral HS/FS Resume

1b

1b

10b

1b

0b

 

 

 

 

 

 

Peripheral Test J/Test K

0b

0b

10b

0b

1b

 

 

 

 

 

 

Revision 1.5 (11-15-07)

26

SMSC USB3280

 

DATASHEET