GENERAL DESCRIPTION

GL852 is Genesys Logic’s brand new Hub solutions which fully comply with Universal Serial Bus Specification Revision 2.0. This series includes GL852.

GL852 embeds an 8-bit RISC processor to manipulate the control/status registers and respond to the requests from USB host. Firmware of GL852 will control its general purpose I/O (GPIO) to access the external EEPROM and then respond to the host the customized PID and VID configured in the external EEPROM. Default settings in the internal mask ROM is responded to the host without having external EEROM. GL852 is designed for customers with much flexibility. The more complicated settings such as PID, VID, and number of downstream ports settings are easily achieved by programming the external EEPROM (Ref. to Chapter 5).

Each downstream port of GL852 supports two-color (green/amber) status LEDs to indicate normal/abnormal status.

To fully meet the performance requirement, GL852 series is a multiple TT hub solution to provide every down stream port with a TT. With the dedicated TT in each down stream port, GL852 can provide the best performance even connect with several Full/Low-Speed devices and running heavy bandwidth-consuming operations concurrently.

FEATURES

• Compliant to USB specification Revision 2.0

− 4 downstream ports

− Upstream port supports both high-speed (HS) and full-speed (FS) traffic

− Downstream ports support HS, FS, and low-speed (LS) traffic

− 1 control pipe (endpoint 0, 64-byte data payload) and 1 interrupt pipe

(endpoint 1, 1-byte data payload) − Backward compatible to USB specification Revision 1.1

• On-chip 8-bit micro-processor

− RISC-like architecture

− USB optimized instruction set

− Dual cycle instruction execution

− Performance: 6 MIPS @ 12MHz

− With 64-byte RAM and 2K internal ROM

− Support customized PID, VID by reading external EEPROM

− Support downstream port configuration by reading external EEPROM

• Multiple Transaction translator (MTT)

− MTT provides respective TT control logics for each downstream port. This is a performance better choice for USB 2.0 hub.