memory products - Al Kossow's Bitsavers

M27256256K (32K x 8) NMOS UV ERASABLE PROM• FAST ACCESS TIME:170ns MAX M27256-1F1200ns MAX M27256-2F1/M27256-20F1250ns MAX M27256F1/M27256F6/M27256-25F1300ns MAX M27256-3F1/M27256-30F1450ns MAX M27256-4F1/M27256-4F6/M27256-45F1• 0 to +70°C STANDARD TEMP. RANGE• -40 to +85°C EXTENDED TEMP. RANGE• SINGLE + 5V POWER SUPPLY• ±10% VCC TOLERANCE AVAILABLE• LOW STANDBY CURRENT (40mA MAX)• TTL COMPATIBLE DURING READ ANDPROGRAM• FAST PROGRAMMING ALGORITHM• ELECTRONIC SIGNATUREDESCRIPTIONThe M27256 is a 262, 144-bit ultraviolet erasable andelectrically programmable read only memory(EPROM). It is organized as 32.768 words by 8 bitsand manufactured using SGS-THOMSON' NMOS­E3 process. The M27256 with its single + 5V powersupply and with an access time of 2oons, is idealfor use .with high performance + 5V microproces­!lor such as Z8, Z80 and Z8000. The M27256 hasan important feature which is to separate the outputcontrol, OJ,!Qtut Enable (OE) from the Chip Enablecontrol (CE). The OE control eliminates buscontention in multiple bus microprocessor systems.The M27256 also features a standby mode whichreduces the power dissipation without increasing accesstime. The active current is 100mA while themaximum standby current is only 40 mA, a 60% saving.The standby mode is achieved by applying aTTL-high signal to the CE input. The M27256 enablesimplementation of new, advanced systems withfirmware intensive architectures. The combinationof the M27256's high density, and new advancedmicroprocessors having megabit addressing capabilityprovides designers with opportunities to engineeruser-friendly, high reliability, high-performancesystems. The M27256 large storage capability enablesit to function as a high density software carrier.Entire operating systems, diagnostics, high-levellanguage programs and specialized application softwarecan reside in a M27256 directly on a system'smemory bus. This permits immediate microprocessoraccess and execution of software and eliminatesthe need for time consuming disk accesses anddownloads. The M27256 has an "Electronic Signature"that allows programmers to automatically identifydevice type and pinout.June 1988FDIP-28(Ceramic BUIl's Eye)(Ordering Information at the end of the datasheet)PIN NAMESAO-A14CEOEVppPIN CONNECTIONS~ VeeA,2 1 27 A'4A7 26 A,3A6 25 A8AS 24 A9A4 23 A11A3 22 OEA2 21 A,DA' 20 CEAD 10 19 0700 11 18 060' [12 17 0502 13 16 04GND"15 035- 7576ADDRESS INPUTCHIP ENABLE INPUTOUTPUT ENABLE INPUT00-07 DATA INPUT/OUTPUT1/1063