SMSC USB2512 - Manual (Page 12)

USB 2.0 High-Speed 2-Port Hub Controller
Datasheet
SMSC USB2512 12 Revision 1.92 (11-28-07)
DATASHEET
3.2 Buffer Type Descriptions
Table 3.4 USB2512 Buffer Type Descriptions
BUFFER DESCRIPTION
I Input.
IPD Input with internal weak pull-down resistor.
IPU Input with internal weak pull-up resistor.
IS Input with Schmitt trigger.
O12 Output 12mA.
OD12 Open drain... 12mA sink.
I/O12 Input/Output buffer with 12mA sink and 12mA source.
I/OSD12 Open drain...12mA sink with Schmitt trigger, and must meet I2C-Bus Specification
Version 2.1 requirements.
ICLKx XTAL clock input.
OCLKx XTAL clock output.
I-R RBIAS.
I/O-U Analog Input/Output Defined in USB specification.
AIO Analog Input/Output.