1. Overview & Functionality

️· Device: Microchip's USB 2.0 2-Port Hub
️· Compliance: Complies with USB 2.0 Specification Rev. 2.0.
️· Transaction Translators (TT): 1 TT per port (Multi-TT configuration)
️· Primary Functions: To connect multiple USB devices to a single USB host.

2. Configuration Options (How the Hub is Set Up)

️· Three Configuration Methods:
- SMBus: (Serial Bus) – Using a serial communication protocol.
- EEPROM: (Electrically Erasable Programmable Read-Only Memory) - Using memory for configuration data.
- Internal Default Settings: Through pins on the chip.
️· Configurable Parameters (These are set through one of the methods above):
- Vendor ID (VID): Unique identifier for the device manufacturer.
- Product ID (PID): Unique identifier for the specific product.
- Device ID (DID): Release number for the device.
- Self-Powered/Bus-Powered: Determines if the hub draws power from the host (Bus-Powered) or has its own power supply (Self-Powered).
- High-Speed Disable: Forces the hub to operate at Full Speed only.
- EOP Disable: Relates to End-of-Packet (EOP) behavior in Full-Speed operation.
- Current Sensing: How current sensing is configured (ganged or none).
- Compound Device: Indicates if the hub is part of a larger, compound device.
- Non-Removable Device: Indicates if a port has a permanently attached device.
- Self-Powered Port DISABLE: Specifies ports that will always be disabled when in Self-Powered mode.
- Bus-Powered Port DISABLE: Specifies ports that will always be disabled when in Bus-Powered mode.
- Dynamic Power: Enables automatic switching between Self-Powered and Bus-Powered modes.
- Over-Current Timer: Delay before reporting an over-current condition.
- Self-Powered Max Power: Maximum power drawn when Self-Powered.
- Bus-Powered Max Power: Maximum power drawn when Bus-Powered.

3. Pin-Based Configuration (Using pins to set some settings)

️· CFG_SEL1 and CFG_SEL0: Determine the configuration method (SMBus, EEPROM, or internal default).
️· NON_REM[1:0]: Configure which ports are non-removable (using internal default settings).
️· SELF_PWR: Detects the availability of a local power source and determines Self-Powered/Bus-Powered status.

4. Important Notes & Limitations

️· Current Consumption Limits:
- Bus-Powered: Must consume no more than 500mA of upstream VBUS current.
- Self-Powered: Can source 500mA of current per available downstream port.
️· Dynamic Power Behavior: The Hub automatically switches to Bus-Powered if the local power source is removed and to Self-Powered when it's restored.
️· Strapping Options: When configured via strapping options declaring a port as non-removable automatically causes the hub controller to report that it is part of a compound device.