Datasheet – SMSC USB2503A User Manual
Page 26
Integrated USB 2.0 Compatible 3-Port Hub
Datasheet
Revision 2.3 (08-27-07)
26
SMSC USB2503/USB2503A
DATASHEET
5.3.9.1
Register 00h: Status/Command (Reset = 0x00)
5.3.9.2
Register 01h: Vendor ID (LSB) (Reset = 0x00)
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
BIT
NUMBER
BIT NAME
DESCRIPTION
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.}
BIT
NUMBER
BIT NAME
DESCRIPTION
7:0
VID_LSB
Least Significant Byte of the Vendor ID.
Table 5.4 SMBus Slave Interface Register Map (continued)
REG
ADDR
R/W
REGISTER NAME
ABBR
BIT 7
(MSB)
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
(LSB)