Am28F020

nized as 256 Kbytes of 8 bits each. AMD's Flash memories offer the most cost-effective and reliable readwrite non-volatile random access memory. The
Am28F020 is packaged in 32-pin PDIP, PLCC, andTSOP versions. It is designed to be reprogrammed anderased in-system or instandardEPROMprogrammers.
The Am28F020 is erased when shipped fromthefactory.The standard Am28F020 offers access times of as fastas 70 ns, allowing high speed microprocessors tooperate without wait states. To eliminate bus contention, the device has separate chip enable  andAMD's Flash memories augment EPROM functionality
with in-circuit electrical erasure and programming.

TheAm28F020 uses a command register to manage thisfunctionality, while maintaining a JEDEC-standard 32-pin pinout. The command register allows for 100% TTLlevel control inputs and fixed power supply levels duringerase and programming, while maintaining maximumEPROM compatibility.AMD's Flash technology reliably stores memory contents even after 10,000 erase and program cycles. TheAMD cell is designed to optimize the erase and pro-advanced tunnel oxide processing and low internalelectric fields for erase and programming operationsproduces reliable cycling. The Am28F020 uses a12.0±5% V
supply input to perform the Flasheraseand Flashrite functions.The highest degree of latch-up protection is achievedwith AMD's proprietary non-epi process. Latch-up proection is provided for stresses up to 100 mA onaddress and data pins from 1 V to V_CC +1 V.

The Am28F020 is byte programmable using 10 µsprogramming pulses in accordance with AMD'sFlashrite programming algorithm. Thetypicalroomtemperature programming time of the Am28F020 isfour seconds. The entire chip is bulk erased using 10ms erase pulses according to AMD's Flasherasealgorithm. Typical erasure at room temperature isaccomplished in less than one second. The windowedpackage and the 1520 minutes required for EPROMerasure using ultraviolet light are eliminated.