HM-6642 pdf datasheet (512 x 8

The HM-6642 is a 512 x 8 CMOS NiCr fusible link
Programmable Read Only Memory in the popular 24 pin,
byte wide pinout. Synchronous circuit design techniques
combine with CMOS processing to give this device high
speed performance with very low power dissipation.
On-chip address latches are provided, allowing easy
interfacing with recent generation microprocessors that use
multiplexed address/data bus structures, such as the 8085.
The output enable controls, both active low and active high,
further simplify microprocessor system interfacing by
allowing output data bus control independent of the chip
enable control. The data output latches allow the use of the
HM-6642 in high speed pipelined architecture systems, and
also in synchronous logic replacement functions.
Applications for the HM-6642 CMOS PROM include low
power handheld microprocessor based instrumentation and
communications systems, remote data acquisition and
processing systems, processor control store, and synchronous
logic replacement.
All bits are manufactured storing a logical “0” and can be
selectively programmed for a logical “1” at any bit location.