Datasheet
Table Of Contents
- Chapter 1 USB251x Hub Family Differences Overview
- Chapter 2 General Description
- Chapter 3 Acronyms
- Chapter 4 Block Diagram
- Chapter 5 Pin Descriptions
- Chapter 6 LED Usage Description
- Chapter 7 Battery Charging Support
- Chapter 8 Configuration Options
- Chapter 9 DC Parameters
- 9.1 Maximum Guaranteed Ratings
- 9.2 Operating Conditions
- Figure 9.1 Supply Rise Time Model
- Table 9.1 DC Electrical Characteristics (continued)
- Table 9.2 Supply Current Unconfigured: Hi-Speed Host (ICCINTHS)
- Table 9.3 Supply Current Unconfigured: Full-Speed Host (ICCINTFS)
- Table 9.4 Supply Current Configured: Hi-Speed Host (IHCH1)
- Table 9.5 Supply Current Configured: Full-Speed Host (IFCC1)
- Table 9.6 USB251x/xi/xA/xAi Supply Current Suspend (ICSBY)
- Table 9.7 USB251xB/xBi Supply Current Suspend (ICSBY)
- Table 9.8 USB251x/xi/xA/xAi Supply Current Reset (ICRST)
- Table 9.9 USB251xB/xBi Supply Current Reset (ICRST)
- Table 9.10 Pin Capacitance for USB251x, USB251xi, USB251xA, USB251xAi
- Table 9.11 Pin Capacitance for USB251xB and USB251xBi
- 9.2.1 Package Thermal Specifications
- Chapter 10 AC Specifications
- Chapter 11 Package Outlines

USB 2.0 Hi-Speed Hub Controller
Datasheet
SMSC USB251x 43 Revision 1.1 (04-26-10)
DATASHEET
8.2.1.17 Register 10h: Power-On Time
8.2.1.18 Register 11h: Language ID High
8.2.1.19 Register 12h: Language ID Low
8.2.1.20 Register 13h: Manufacturer String Length
8.2.1.21 Register 14h: Product String Length
8.2.1.22 Register 15h: Serial String Length
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
adequate on that port.
BIT
NUMBER BIT NAME DESCRIPTION
7:0 LANG_ID_H USB Language ID (Upper 8 bits of a 16-bit ID field)
BIT
NUMBER BIT NAME DESCRIPTION
7:0 LANG_ID_L USB Language ID (Lower 8 bits of a 16-bit ID field)
BIT
NUMBER BIT NAME DESCRIPTION
7:0 MFR_STR_LEN Manufacturer String Length
When supported, the maximum string length is 31 characters.
BIT
NUMBER BIT NAME DESCRIPTION
7:0 PRD_STR_LEN Product String Length
When supported, the maximum string length is 31 characters.
BIT
NUMBER BIT NAME DESCRIPTION
7:0 SER_STR_LEN Serial String Length
When supported, the maximum string length is 31 characters.