27C256 Datasheet | National Semiconductor

Description The NM27C256 is a 256K Electrically Programmable Read Only Memory It is manufactured in National’s latest CMOS split gate EPROM technology which enables it to operate at speeds as fast as 120 ns access time over the full operating range The NM27C256 provides microprocessor-based systems extensive storage capacity for large portions of operating system and application software Its 120 ns access time provides high speed operation with high-performance CPUs The NM27C256 offers a single chip solution for the code storage requirements of 100% firmware-based equipment Frequently-used software routines are quickly executed from EPROM storage greatly enhancing system utility The NM27C256 is configured in the standard EPROM pinout which provides an easy upgrade path for systems which are currently using standard EPROMs The NM27C256 is one member of a high density EPROM Family which range in densities up to 4 Mb Features High performance CMOS 120 ns access time JEDEC standard pin configuration 28-pin DIP package 32-pin chip carrier Drop-in replacement for 27C256 or 27256 Manufacturer’s identification code Block Diagram TL D 10833 - 1 TRI-STATE is a registered trademark of National Semiconductor Corporation HPCTM is a trademark of National Semiconductor Corporation C1995 National Semiconductor Corporation TL D 10833 RRD-B30M65 Printed in U S A Connection Diagrams 27C080 27C040 27C020 27C010 27C512 A19 A16 A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 O0 O1 O2 GND XX VPP XX VPP XX VPP A16 A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 O0 O1 O2 GND A16 A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 O0 O1 O2 GND A16 A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 O0 O1 O2 GND A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 O0 O1 O2 GND TL D 10833 - 2 27C512 27C010 27C020 27C040 27C080 DIP NM27C256 VCC A14 A13 A8 A9 A11 OE VPP A10 CE PGM O7 O6 O5 O4 O3 VCC XX A14 A13 A8 A9 A11 OE A10 CE O7 O6 O5 O4 O3 VCC A17 A14 A13 A8 A9 A11 OE A10 CE O7 O6 O5 O4 O3 VCC A18 A17 A14 A13 A8 A9 A11 OE A10 O7 O6 O5 O4 O3 VCC A18 A17 A14...