M27C128A

The M27C128A has the following features including VERY FAST ACCESS TIME: 120ns;COMPATIBLE WITH HIGH SPEED MICROPROCESSORS, ZERO WAIT STATE;LOW POWER "CMOS"CONSUMPTION:Active Current 30mA,Standby Current 100A;PROGRAMMING VOLTAGE: 12.75V;ELECTRONIC SIGNATURE FOR AUTOMATED PROGRAMMING;PROGRAMMING TIMES OF AROUND 2sec(PRESTO II ALGORITHM).

The M27C128A is a high speed 131,072 bit UV erasable and electrically programmable memory EPROM ideally suited for microprocessor systems requiring large programs. It is organized as 16,384 by 8 bits.The 28 pin Window Ceramic Frit-Seal Dual-in-Line package has transparent lid which allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can then be written to the device by following the programming procedure.Except for the rating "Operating Temperature Range", stresses above those listed in the Table "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the SGS-THOMSON SURE Program and other relevant quality documents.

The M27C128A has two control functions, both of which must be logically active in order to obtain data at the outputs. Chip Enable (E) is the power control and should be used for device selection.Output Enable(G) is the output control and should be used to gate data to the output pins, independent of device selection.  Assuming that the addresses are stable, the address access time (tAvQv) is equal to the delay from E to output (tELQV).  Data is available at the output after a delay of tGLOV from the falling edge of G, assuming that E has been low and the addresses have been stable for at least tAVQV-tGLQV.The modes of operation of the M27C128Aare listed in the Operating Modes table. A single 5V power supply is required in the read mode. All inputs are TTL levels except for VPP and 12V on A9 for Electronic Signature.