The AT27C512R is a low-power, high-performance 524,288-bit one-time programma- ble read-only memory (OTP EPROM) organized 64K by 8 bits. It requires only one 5V power supply in normal read mode operation. Any byte can be accessed in less than 45 ns, eliminating the need for speed reducing WAIT states on high-performance microprocessor systems. Atmel’s scaled CMOS technology provides high-speed, lower active power consump- tion, and significantly faster programming. Power consumption is typically only 8 mA in Active Mode and less than 10 µA in Standby. The AT27C512R is available in a choice of industry-standard JEDEC-approved one- time programmable (OTP) plastic PDIP, PLCC, SOIC, and TSOP packages. All devices feature two-line control (CE, OE) to give designers the flexibility to prevent bus contention. With 64K byte storage capability, the AT27C512R allows firmware to be stored reli- ably and to be accessed by the system without the delays of