USB2502

DS000002248A-page 24

 2007 - 2016 Microchip Technology Inc.

5.3.9.15

Register 0Eh: Hub Controller Max Current For Self Powered Operation (Reset = 0x00)

5.3.9.16

Register 0Fh: Hub Controller Max Current For Bus Powered Operation (Reset = 0x00)

5.3.9.17

Register 10h: Power-On Time (Reset = 0x00)

5.3.9.18

Undefined Registers

The registers shown in Table 5-4 are the defined registers in the Hub. Reads to undefined registers return 00h. Writes

to undefined registers have no effect and do not return an error.

5.3.9.19

Reserved Registers

Unless otherwise instructed, only a ‘0’ may be written to all reserved registers or bits.

5.4

Default Configuration Option:

The Microchip Hub can be configured via its internal default configuration. (please see for specific details on how to

enable default configuration.

Please refer to Table 5-1 on page 15 for the internal default values that are loaded when this option is selected.

5.5

Default Strapping Options:

The Microchip Hub can be configured via a combination of internal default values and pin strap options. Please see

Table 4-1, "2-Port Hub Pin Descriptions" for specific details on how to enable the default/pin-strap configuration option.

The strapping option pins only cover a limited sub-set of the configuration options. The internal default values will be

used for the bits & registers that are not controlled by a strapping option pin. Please refer to Table 5-1 on page 15 for

the internal default values that are loaded when this option is selected.

Bit Number

Bit Name

Description

7:0

HC_MAX_C_SP

Hub Controller Max Current Self-Powered: Value in 2mA 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 does NOT include the power consumption of a permanently attached

peripheral if the hub is configured as a compound device.

Note:

The USB 2.0 Specification does not permit this value to exceed

100mA

A value of 50 (decimal) indicates 100mA, which is the default value.

Bit Number

Bit Name

Description

7:0

HC_MAX_C_BP

Hub Controller Max Current Bus-Powered: Value in 2mA increments that the

Hub consumes from an upstream port (VBUS) when operating as a bus-

powered hub. This value will include the hub silicon along with the combined

power consumption (from VBUS) of all associated circuitry on the board. This

value will NOT include the power consumption of a permanently attached

peripheral if the hub is configured as a compound device.

A value of 50 (decimal) would indicate 100mA, which is the default value.

Bit Number

Bit Name

Description

7:0

POWER_ON_TIME

Power On Time: The length of time that it takes (in 2 ms intervals) from the

time the host initiated power-on sequence begins on a port until power is good

on that port.