The ISP1130 integrates a Universal Serial Bus (USB) hub with a keyboard controller into a single chip, which complies with Universal Serial Bus Specification Rev. 1.1 and the USB Device Class Definition for Human Interface Devices (HID). The hub has 1 to 2 downstream ports and 1 to 3 non-removable embedded functions, one of which is dedicated to the keyboard operation. The hub controller is fully implemented in hardware, ensuring a fast response to host requests. The integrated 5 V to 3.3 V regulator allows direct connection to the USB power supply VBUS. The downstream ports are either bus-powered or hybrid-powered and can interface low-power USB devices such as a joystick or a mouse. ISP1130 uses SoftConnectTM technology to connect to the USB host upon detection of VBUS. The low power consumption in `suspend' mode allows easy design of equipment that is compliant with the ACPITM, OnNowTM and USB power management requirements. The integrated keyboard controller is based on the 80C51 family and has 8 kbytes of mask ROM and 256 bytes of data RAM. The code memory is protected against reading by an external device. A built-in watchdog timer resets the device in case of a microcontroller hang-up. To reduce power consumption, the microcontroller can be put in sleep mode or power-down mode. c