SMSC USB2512B Manual De Usuario

USB 2.0 Hi-Speed Hub Controller

SMSC USB251x

49

Revision 1.0 (3-11-09)

7:0

PRTR34

PortMap register for ports 3 & 4.

When a hub is enumerated by a USB host controller, the hub is only 

permitted to report how many ports it has; the hub is not permitted to select 

a numerical range or assignment.  The host controller will number the 

downstream ports of the hub starting with the number '1', up to the number 

of ports that the hub reported having.  

The host's port number is referred to as "Logical Port Number" and the 

physical port on the hub is the “Physical Port Number". When mapping mode 

is enabled (see PRTMAP_EN in Register 08h: Configuration Data Byte 3) 

the hub's downstream port numbers can be mapped to different logical port 

numbers (assigned by the host).

OEM must ensure that contiguous logical port numbers are used, 
starting from #1 up to the maximum number of enabled ports; this 
ensures that the hub's ports are numbered in accordance with the 
way a host will communicate with the ports.

Bit [7:4]

‘0000’

Physical Port 4 is Disabled

‘0001’

Physical Port 4 is mapped to Logical Port 1

‘0010’

Physical Port 4 is mapped to Logical Port 2

‘0011’

Physical Port 4 is mapped to Logical Port 3

‘0100’

Physical Port 4 is mapped to Logical Port 4

‘0101’

Physical Port 4 is mapped to Logical Port 5

‘0100’

Physical Port 4 is mapped to Logical Port 6

‘0111’

Physical Port 4 is mapped to Logical Port 7

‘1000’

to

‘1111’

Reserved, will default to ‘0000’ value

Bit [3:0]

‘0000’

Physical Port 3 is Disabled

‘0001’

Physical Port 3 is mapped to Logical Port 1

‘0010’

Physical Port 3 is mapped to Logical Port 2

‘0011’

Physical Port 3 is mapped to Logical Port 3

‘0100’

Physical Port 3 is mapped to Logical Port 4

‘0101’

Physical Port 3 is mapped to Logical Port 5

‘0110’

Physical Port 3 is mapped to Logical Port 6

‘0111’

Physical Port 3 is mapped to Logical Port 7

‘1000’

to

‘1111’

Reserved, will default to ‘0000’ value