USB KEYBOARD APPARATUS AND METHOD CAPABLE OF SUPPORTING N-KEY ROLLOVER WITH BIOS COMPATIBILITY

摘要

An N-key rollover USB keyboard apparatus according to embodiments of the present invention can include a descriptor storage unit including a descriptor, in which a report size, which is a field size of an item to be reported to a host device in compliance with the standard of a universal serial bus (USB) human interface device (HID), and a report count representing the number of fields of the item are declared, a USB device controller for analyzing a request received therein from the host device to set one of a boot protocol mode and a report protocol mode, and for outputting a report containing key codes, which are created through the key pressing of a user, as items to the host device, and a report creating unit for creating a report containing six typical key codes according to a boot protocol if the set protocol mode is the boot protocol mode, for creating a report containing key codes for typical keys by number corresponding to the report count declared in the descriptor storage unit if the set protocol mode is the report protocol mode, and for outputting the creating report to the USB device controller. [Reference numerals] (10) N-key rollover USB keyboard apparatus; (12) Report generating unit; (13) descriptor storage unit; (131) Usage table; (132) Report descriptor; (14) USB device controller; (141) Protocol setting unit; (15) USB interface