USB82640 Datasheet, PDF (38/64 Pages) Microchip Technology – Automotive USB 2.0 Hub and Flash Media Card Controller Combo

USB82640
7.3.3.31 F2h: PortMap 12
Bit
Byte Name
7:0
PRTM12
Description
PortMap Register for Ports 1 and 2
When a hub is enumerated by a USB host controller, the hub is only permit-
ted 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 down-
stream 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 remapping mode is
enabled (see PRTMAP_EN in Register 08h: Configuration Data Byte 3) the
hub's downstream port numbers can be remapped to different logical port
numbers (assigned by the host).
Note:
The OEM must ensure that contiguous logical port numbers are
used, starting from number 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.
TABLE 7-5:
Bit [7:4]
Bit [3:0]
PORTMAP REGISTER FOR PORTS 1 & 2
0000
0001
0010
0011
0100
to
1111
0000
0001
0010
0011
0100
to
1111
Physical port 2 is disabled
Physical port 2 is mapped to Logical port 1
Physical port 2 is mapped to Logical port 2
Physical port 2 is mapped to Logical port 3
Illegal; Do not use
Physical port 1 is disabled
Physical port 1 is mapped to Logical port 1
Physical port 1 is mapped to Logical port 2
Physical port 1 is mapped to Logical port 3
Illegal; Do not use
DS60001312A-page 38
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