SMSC USB2503 Manual De Usuario

Integrated USB 2.0 Compatible 3-Port Hub

Revision 2.3 (08-27-07)

26

SMSC USB2503/USB2503A

0Ch

R/W

Max Power (Self)

MAXPS

7

6

5

4

3

2

1

0

0Dh

R/W

Max Power (Bus)

MAXPB

7

6

5

4

3

2

1

0

0Eh

R/W

Hub Controller 
Max Current (Self)

HCMCS

7

6

5

4

3

2

1

0

0Fh

R/W

Hub Controller 
Max Current (bus)

HCMCB

7

6

5

4

3

2

1

0

10h

R/W

Power-on Time

PWRT

7

6

5

4

3

2

1

0

7:3

Reserved

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

2

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.

1

WRITE_PROT

Write Protect: The external SMBus host sets this bit after the Hub’s internal 
memory is loaded with configuration data. {Note: The External SMBus Host 
is responsible for verification of downloaded data.}

0 = The internal memory (address range 01-10h) is not write protected.
1 = The internal memory (address range 01-10h) is “write-protected” to 
prevent unintentional data corruption.}

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

0

USB_ATTACH

USB Attach & power-down the SMBus Interface. 

0 = Default; SMBus slave interface is active.
1 = Hub will signal a USB attach event to an upstream device, Note: SMBus 
Slave interface will completely power down after the ACK has completed.

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

7:0

VID_LSB

Least Significant Byte of the Vendor ID.