How to save data on serial EEPROM like a database ?

[iugmoh]

but i think that there are an article or paper for the effiecient way of saving data , I don't know where I see it.

[skimask]

but i think that there are an article or paper for the effiecient way of saving data , I don't know where I see it.

Ok,
ID Time Date #of register
=================================
1200312 8:30 12/9/2009 10

ID - seems to be a 7 digit number. You can either store that as a single LONG, or 2 WORD's, either in hex format, or BCD... Figure 28 bits

Time - hours/minutes - 24 hours = 5 bits, 60 minutes = 6 bits, 11 bits for time, 11 bits for this

Date - Month/Day/Year - 12 months = 4 bits, 31 days = 5 bits, Year-call it 64 years total, offset by +2008, 6 bits; 15 bits total

Register - don't know how many registers, but I'll assume 16 (numbered 0-15), 4 bits there.

28 bits for ID + 11 bits for time + 15 bits for date + 4 bits for register = 58 bits, 8 bytes total, with 6 leftover for whatever else.

Then you play with the bits/byte, putting thing where they need to go...AND'ing them out here, OR'ing them in there. Whatever works for you.

So the bits in the 8 bytes look like:
IIIIIIII IIIIIIII IIIIIIII IIIIHHHH HMMMMMMm mmmddddd yyyyyyRR RRxxxxxx
I = ID
H = hours
M = minutes
m = month
d = day
y = year (offset by 2008, add 2008 to the total)
R = register
x = spare

[Jerson]

By efficient, I assume you are looking for utilising the EEPROM to its stated write endurance. I do recall having seen an article about this perhaps on this site. Or maybe, is it Microchip site?

JF

[iugmoh]

Thanks alot for skimask for the importnant information that clearify our problem