View sae81c54 datasheet:

SAE 81C54 CMOS RAM Preliminary DataACMOS IC Features 512 x 8 bit-organization Multiplexed address and data bus Tristate address and data lines On-chip address register Very low current consumption: 1 µA at 5.5 V during standby Dual chip selection P-DIP-16-1 Wide supply voltage range from 2.5 V to 5.5 V Fully compatible 5 V ± 10 % Data retention up to 1.0 V Temperature range – 40 to 110 °C Type Ordering Code Package SAE 81C54 P Q67100-H8486 P-DIP-16-1 The SAE 81C54 P is a static 4096-bit RAM (512 words by 8 bits) in Advanced CMOS technology. The address and data bus in the multiplex operation allows directly interfaces to 8-bit microprocessors/microcontroller families, e.g. SAB 8086, SAB 8088, SAB 8051. Due to its low power dissipation of less than 1 µA in sta