The GL854G is Genesys Logic’s premium 7-port hub solution which fully complies with Universal Serial Bus Specification Revision 2.0. The GL854G implements a multiple TT architecture that provides dedicated TT to each downstream (DS) port, which guarantees Full-Speed(FS) data passing bandwidth when multiple FS device perform heavy loading operations. The controller inherits Genesys Logic’s cutting edge technology on cost and power efficient serial interface design. The GL854G has proven compatibility, lower power consumption figures and better cost structure above all USB 2.0 hub solutions worldwide.
The GL854G implements multiple hub configuration features onto an internal mask ROM, which traditionally requires an external EEPROM. The microprocessor detects general purpose I/O (GPIO) status during the initial stage to configure hub settings such as (1) declaration of compound device (2) gang/individual mode selection…etc. The external EEPROM can be removed if no vendor specified PID/VID or product string is required for the application.
The GL854G provides a 12MHz clock output that can be used as a reference clock source for multi-chip, hub compound applications. The output clock provides enough driving capacity to support up to 2 devices connected to the downstream port
A lower bom cost can be achieved as the GL854 uses a single external 12 MHz crystal / Oscillator clock input, has an On-chip 5V to 3.3V power regulator, with built-in upstream port 1.5K? pull-up and downstream port 15K? pull-down resistors, and supports a low-cost 24C02 EEPROM.
The GL854 is available in a 64 pin LQFP package (7x7mm). Typical applications include, UMPC/MID, motherboard on-board applications, consumer electronics, monitor built-in hub and embedded systems.