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REPLACING 8051 RAM

WITH DALLAS TIMEKEEPING RAM
by Bruce Renyolds

Start ý Clock Operation ý Donýt Need 32 KB? ý Replacing EPROMs ý Sources and PDF

REPLACING EPROMS

Letýs explore another 8051 control board issue thatýs been a time-consuming burden on developers for a long timeýthe dreaded burn/erase cycles during the debugging phase using the old EPROM. Been there, done that, but not again.

You can use an EPROM emulator, but I can never quite keep the ribbon cable out of the way and I usually have more than enough cables and wires already cluttering my lab bench anyway. Substituting the ý2764 EPROM or ý2864 EEPROM with the DS1225Y 64-KB nonvolatile SRAM can eliminate the erase time.

Many EPROM programmers program the DS1225Y the same as the ý2764 so you can keep on reprogramming it without erasing it first. Need more than 8 KB? Just drop in the DS1230Y 32-KB version of the NV SRAM. Try finding a ý2764 or ý2864 with unlimited write cycles.

Nearly any application using standard SRAM can be enhanced with the ability to date and time stamp events or to execute certain subroutines during specific time periods. In fact, many embedded control systems would be worthless without this simple ability.

Rather than design new control systems to meet the ever-increasing demands on existing equipment, you can check out other quick and cost-effective solutions. When thereýs no alternative but a complete redesign of an existing control system, the engineer with the quick, cost-effective solution will probably move to the head of the class.

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