Am28F020A

The Am28F020A is a 2 Megabit Flash memory orga- nized as 256 Kbytes of 8 bits each. AMD's Flash mem- ories offer the most cost-effective and reliable read/ write non-volatile random access memory. The Am28F020A is packaged in 32-pin PDIP, PLCC, and TSOP versions. It is designed to be reprogrammed and erased in-system or in standard EPROM programmers. The Am28F020A is erased when shipped fromthe factory.

The standard Am28F020A offers access times of as fast as 70 ns, allowing high speed microprocessors to operate without wait states. To eliminate bus conten- tion, the device has separate chip enable (CE#) and output enable(OE#) controls. AMD's Flash memories augment EPROM functionalitywith in-circuit electrical erasure and programming.

TheAm28F020A uses a command register to manage thisfunctionality. The command register allows for 100% TTL level control inputs and fixed power supply levels during erase and programming, while maintainingmaximum EPROM compatibility.

The Am28F020A is compatible with the AMD Am28F256A, Am28F512A, and Am28F010A Flash memories. All devices in the Am28Fxxx family follow the JEDEC 32-pin pinout standard. In addition, all devices within this family that offer Embedded Algo- rithms use the same command set. This offers designers the flexibility to retain the same device foot-print and command set, at any density between 256 Kbits and 2 Mbits.AMD's Flash technology reliably stores memory con-tents even after 100,000 erase and program cycles.

The AMD cell is designed to optimize the erase and programming mechanisms. In addition, the combina- tion of advanced tunnel oxide processing and low internal electric fields for erase and programming oper- ations produces reliable cycling. The Am28F020A uses a 12.0±5% VPP supply input to perform the erase and programming functions.

The highest degree of latch-up protection is achiev with AMD's proprietary non-epi process. Latch-up ptection is provided for stresses up to 100 mA address and data pins from 1 V to VCC +1 V.

AMD's Flash technology combines years of EPROM and EEPROM experience to produce the highest levelsof quality, reliability, and cost effectiveness. The Am28F020A electrically erases all bits simultaneously using Fowler-Nordheim tunneling. The bytes are programmed one byte at a time using the EPROM programming mechanism of hot electron injection.