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Help with programming an EEPROM

compusmola

Nov 23, 2015
1
Joined
Nov 23, 2015
Messages
1
Hi,

I want to programe an EEPROM 27C256 that allows me to convert a BCD number to a binary number. I want to introduce 3 bcd numbers (12 bits) and obtain a 8 bits binary number (from 0 to 255). I have tried to programe it but i don't know how to do it. Does anyone have this file?

Thanks
 

hevans1944

Hop - AC8NS
Jun 21, 2012
4,875
Joined
Jun 21, 2012
Messages
4,875
With only 1000 different BCD numbers from 000 to 999, clearly you don't need to use every one of the 32,768 locations available in the EEPROM. So just connect the BCD bits to the first twelve address bits, A0 through A11, and program those locations with the binary equivalents of the three decimal numbers from 000 to 999.

Some of the bit combinations will not be used of course since a BCD representation only goes from 0 (0000) to 9 (1001) whereas the binary values for four bits would also include A (1010) through F (1111). Make sure address bits A12, A13, and A14 are tied to logic zero. Note you could program the EEPROM to convert a 4-digit set of BCD numbers and still have 55,537 locations left over.
 
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