Datasheet

 2010 - 2015 Microchip Technology Inc. DS00001692C-page 25
USB251xB/xBi
5.1.12 REGISTER 0BH: PORT DISABLE FOR BUS-POWERED OPERATION
5.1.13 REGISTER 0CH: MAX POWER FOR SELF-POWERED OPERATION
5.1.14 REGISTER 0DH: MAX POWER FOR BUS-POWERED OPERATION
Bit Number Bit Name Description
7:0 PORT_DIS_BP Port Disable Bus-Powered: disables one or more ports.
0 = port is available
1 = port is disabled
Bit 7 : rsvd
Bit 6 : rsvd
Bit 5 : rsvd
Bit 4 : controls port 4
Bit 3 : controls port 3
Bit 2 : controls port 2
Bit 1 : controls port 1
Bit 0 : rsvd
During self-powered operation when mapping mode is disabled (
PRTMAP_EN
= 0), this selects the ports which will be permanently disabled.These ports are
then unavailable and cannot be enabled or enumerated by a host controller.
The ports can be disabled in any order, where the internal logic will
automatically report the correct number of enabled ports to the USB host. The
active ports will be reordered in order to ensure proper function.
When using the internal default option, the PRT_DIS_P[x:1] and
PRT_DIS_M[x:1] pins disable the appropriate ports.
Bit Number Bit Name Description
7:0 MAX_PWR_SP Max Power Self-Powered: the value in 2 mA increments that the hub
consumes from an upstream port (VBUS) when operating as a self-powered
hub. This value includes the hub silicon along with the combined power
consumption (from VBUS) of all associated circuitry on the board. This value
also includes the power consumption of a permanently attached peripheral if
the hub is configured as a compound device. The embedded peripheral
reports 0 mA in its descriptors.
Note: The USB 2.0 Specification does not permit this value to exceed
100 mA
Bit Number Bit Name Description
7:0 MAX_PWR_BP Max Power Bus-Powered: the value in 2 mA increments that the hub
consumes from an upstream port (VBUS) when operating as a bus-powered
hub. This value includes the hub silicon along with the combined power
consumption (from VBUS) of all associated circuitry on the board. This value
also includes the power consumption of a permanently attached peripheral if
the hub is configured as a compound device. The embedded peripheral
reports 0 mA in its descriptors.