The CY7C1049D-10VXI is a 4MB high-performance CMOS Static Random Access Memory (SRAM) organized as 512K words by 8-bit. Easy memory expansion is provided by an active LOW chip enable, an active LOW output enable and tri-state drivers. Writing to the device is accomplished by taking chip enable and write enable inputs LOW. Data on the eight I/O pins is then written into the location specified on the address pins. Reading from the device is accomplished by taking chip enable and output enable LOW while forcing write enable HIGH. Under these conditions, the contents of the memory location specified by the address pins will appear on the I/O pins. The eight input/output pins are placed in a high-impedance state when the device is deselected, the outputs are disabled or during a write operation The CY7C1049D is suitable for interfacing with processors that have TTL I/P levels. It is not suitable for processors that require CMOS I/P levels.