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 5V to 3.3V 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 SoftConnect™ 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 ACPI™, OnNow™ and USB power management requirements. The integrated keyboard controller is based on the 80C51 family and has 8KB 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. A serial I2C-bus interface is provided for optional.