USB MultiSwitchTM Hub

Datasheet

 

 

7.1.4.64

Register FFh: Status/Command (Reset = 0x00)

 

 

 

BIT

 

 

NUMBER

BIT NAME

DESCRIPTION

 

 

 

7:3

Reserved

Reserved. {Note: Software must never write a ‘1’ to these bits}

2

INTF_PW_DN

SMBus Interface Power Down

 

 

0 = Interface is active

 

 

1 = Interface power down after ACK has completed.

 

 

{Note: This bit is write once and is only cleared by assertion of the external

 

 

RESET_N pin.}

1

RESET

Reset the SMBus Interface and internal memory back to RESET_N assertion

 

 

default settings. {Note: During this reset, this bit is automatically cleared to its

 

 

default value of 0.}

 

 

0 = Normal Run/Idle State.

 

 

1 = Force a reset of the registers to their default state.

 

 

If the USB_ATTCH bit is set, then this bit will only reset the non write-protected

 

 

registers!

0

USB_ATTACH

USB Attach (and write protect).

 

 

0 = SMBus slave interface is active.

 

 

1 = Hub will signal a USB attach event to an upstream device, and the internal

 

 

memory (address range 00h-F0h) is “write-protected” to prevent unintentional

 

 

data corruption.}

 

 

{Note 1: This bit is write once and is only cleared by assertion of the external

 

 

RESET_N pin.}

 

 

{Note 2: If the SMBus interface is kept active after this bit is set, the

 

 

PORT_ASSIGN_12, PORT_ASSIGN_34 PORT_ASSIGN_56,

 

 

PORT_ASSIGN_7 and PORT_LOCKOUT registers may be continuously

 

 

written to reconfigure port ownership.

SMSC USB2524

39

Revision 1.91 (08-22-07)

 

DATASHEET