Author Topic: 93LC46/56/66 Serial EEPROM - A Few questions.  (Read 3024 times)

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Offline erikhedbTopic starter

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93LC46/56/66 Serial EEPROM - A Few questions.
« on: February 01, 2015, 06:43:47 pm »
Im trying to dump the content of a salvaged ATC 93LC46 Chip. The 93LCXX chip seams to be very common and also made by many different manufacturers.

http://pdf.datasheetcatalog.com/datasheet/Ceramate/mXruxvr.pdf

Have done a few Arduino and AVR projects but cant get a grip ion this chip.

I do know that I must shift out bits with commands and then shift in bits to read the EEPROM.

byte READ  = 0b110;                //read instruction
byte WRITE = 0b101;               //write instruction
etc

In order to read I must shift out the read instruction together with the adress to read. After that shift in the data in that adress.

The data sheet specifies:

START BIT 1
READ 10
ADDRESS A5 A4 A3 A2 A1 A0
DATA D15 - D0 25

So what do I shift out to get something in?

How do I specify the different adressess?

A0 = 160 = 10100000
A1 = 161 = 10100001

Also, how are the memory organized. A0-A5 is just six differend values.

Can someone please point me in the right direction?


/Erik


More, its a petty the timing diagrams are so short, a full low-high sequence would explain it all.

Also, is this a SPI device? I suspect it might be.
« Last Edit: February 01, 2015, 07:01:48 pm by erikhedb »
 

Offline elgonzo

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Re: 93LC46/56/66 Serial EEPROM - A Few questions.
« Reply #1 on: February 01, 2015, 06:51:12 pm »
How do I specify the different adressess?

A0 = 160 = 10100000
A1 = 161 = 10100001
/Erik

Seems you have a misunderstanding. A0 ... A5 are address bits. Thus, you have 6 address bits, giving an address range of 0...63.

Also, read the datasheet carefully, especially about timing and necessary clock impulses. It might be that only 6 address bits are used by this chip but the protocol still demanding 8 (or less/more) clock impulses as if there were 8 address bits...
 

Offline erikhedbTopic starter

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Re: 93LC46/56/66 Serial EEPROM - A Few questions.
« Reply #2 on: February 01, 2015, 07:11:51 pm »
Ah,

So A0 is address bit 0 etc.

So: 000000 is the start address and 111111 is the end address?

Also 1024 / 64 = 16 -> Shift in D15-D0  ie data bit 0 to Data bit 15.

Thanks
 

Offline elgonzo

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Re: 93LC46/56/66 Serial EEPROM - A Few questions.
« Reply #3 on: February 01, 2015, 07:14:53 pm »
So: 000000 is the start address and 111111 is the end address?

Yupp.
 

Offline woodchips

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Re: 93LC46/56/66 Serial EEPROM - A Few questions.
« Reply #4 on: February 02, 2015, 05:39:35 pm »
Don't know which manufacturer you have, but these chips can work in 8 or 16 bit mode. And some will only work either in 8 or 16 bit mode.
 


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