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TUSB9261

SLLSE67I – MARCH 2011 – REVISED MARCH 2016

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Copyright © 2011–2016, Texas Instruments Incorporated

Signal Descriptions – I/O Definitions

I/O TYPE

DESCRIPTION

I

Input

O

Output

I/O

Input/output

PU

Internal pullup resistor

PD

Internal pulldown resistor

PWR

Power signal

Clock and Reset Signals

PIN

I/O

DESCRIPTION

NAME

NO.

GRSTz

4

I

PU

Global power reset. This reset brings all of the TUSB9261 internal registers to their default

states. When GRSTz is asserted, the device is completely nonfunctional.

XI

52

I

Crystal input. This terminal is the crystal input for the internal oscillator. The input may alternately

be driven by the output of an external oscillator. When using a crystal, a 1-M

Ω feedback resistor

is required between X1 and XO.

XO

54

O

Crystal output. This terminal is the crystal output for the internal oscillator. If XI is driven by an

external oscillator, this pin may be left unconnected. When using a crystal, a 1-M

Ω feedback

resistor is required between X1 and XO.

FREQSEL[1:0]

31, 30

I

PU

Frequency select. These terminals indicate the oscillator input frequency and are used to

configure the correct PLL multiplier. The field encoding is as follows:

FREQSEL[1]

FREQSEL[0]

INPUT CLOCK FREQUENCY

1

1

40 MHz

(1)

Note that the default firmware and reference design for the TUSB9261 have the SATA TXP/TXM swapped for ease of routing in the

reference design. If you plan to use the TI default firmware please review the reference design in the TUSB9261 DEMO User’s Guide

(SLLU139) for proper SATA connection.

SATA Interface Signals(1)

PIN

I/O

DESCRIPTION

NAME

NO.

SATA_TXP

57

O

Serial ATA transmitter differential pair (positive)

SATA_TXM

56

O

Serial ATA transmitter differential pair (negative)

SATA_RXP

60

I

Serial ATA receiver differential pair (positive)

SATA_RXM

59

I

Serial ATA receiver differential pair (negative)

USB Interface Signals

PIN

I/O

DESCRIPTION

NAME

NO.

USB_SSTXP

43

O

SuperSpeed USB transmitter differential pair (positive)

USB_SSTXM

42

O

SuperSpeed USB transmitter differential pair (negative)

USB_SSRXP

46

I

SuperSpeed USB receiver differential pair (positive)

USB_SSRXM

45

I

SuperSpeed USB receiver differential pair (negative)

USB_DP

36

I/O

USB high-speed differential transceiver (positive)

USB_DM

35

I/O

USB high-speed differential transceiver (negative)

USB_VBUS

50

I

USB bus power

USB_R1

38

O

Precision resistor reference. A 10-k

Ω ±1% resistor should be connected between R1 and R1RTN.

USB_R1RTN

39

I

Precision resistor reference return