Datasheet – SMSC USB2502 User Manual
Page 31
2-Port USB 2.0 Hub Controller
Datasheet
SMSC USB2502
31
Revision 2.3 (08-27-07)
DATASHEET
5.3.9.14
Register 0Dh: Max Power For Bus Powered Operation (Reset = 0x00)
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
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.
BIT
NUMBER
BIT NAME
DESCRIPTION
7:0
MAX_PWR_BP
Max Power Bus_Powered: Value in 2mA 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, and the embedded peripheral reports
0mA in its descriptors.
A value of 50 (decimal) indicates 100mA.
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.