PS/2 Mouse Interface

Publisher Summary The Personal System 2 (PS/2) mouse is a standard interface to both computers and many Field Programmable Gate Array (FPGA) development kits. The PS/2 mouse originated in the 1980s with the proliferation of the IBM PC. The PS/2 interface is essentially a custom serial interface with one device supported per connector. The PS/2 mouse supports communication from the mouse to the host and vice versa, and the supply is provided from the host to the mouse in the form of a 5 V line. The chapter presents an overview of a simple VHSIC hardware description language (VHDL)—where VHSIC stands for very high speed integrated circuit—interface code to enable the designer to use a mouse, primarily on a standard FPGA development kit. It shows how to handle a basic PS/2 signal for a mouse and then store the data in three bytes for further processing. Two methods are discussed in the chapter for collecting the data: using the PS/2 clock and using a sampled version with a much faster internal clock.