How to know, 8 or 16 bit read on 93C66 Eeprom?

**soxten** · 16th August, 2016, 02:35 PM

I have a UCH from Renault Clio (Sagem) as having 93C66 Eeprom
This Eeprom I can read 8 or 16bit.
How do I know what bit I need to read?

Is there any way to know and understand if it should be 8 or 16 bit read?

ex Saab CIM with 93C66 I read as 8bit and it works perfect.

**gjenkins0** · 16th August, 2016, 04:35 PM

Easy way to tell : read as 8 and the 16, save your files , try write 8bit back to eeprom and see if data has written same , if verify has success then it is 8 bit if you have errors then its 16 bit

**ucokseparoh** · 16th August, 2016, 07:13 PM

8bit.jpg

there you go...

*looks like the pict posted too small to be read

here it is what's written in pict : Pin 7 is tied to pin 5 that makes a 8bit. Mode read.

**soxten** · 16th August, 2016, 10:23 PM

If I understand correct.

This is 8bit (Saab 9-3 CIM 93C66x8)
ImageUploadedByTapatalk1471382528.210131.jpg

And this is 16bit (Sagem UCH Renault Clio 93C66x16)
ImageUploadedByTapatalk1471382559.180764.jpg

**ray-ray** · 17th August, 2016, 01:20 AM

Finally someone understood (EEPROM is 8 or 16 bit off the board) once on the board if pin 7 is tied to pin 5 then read as 8bit mode. In the USA we read in circuit so alway check pin 7 & pin 5 to get the right read.

**Zmann** · 17th August, 2016, 02:57 AM

I think you meant pin 6, org pin.

**martin292009** · 17th August, 2016, 03:36 AM

read 8 bit.

**ray-ray** · 17th August, 2016, 03:49 AM

Correction 6&5 org.&ground = 8bit.

**soxten** · 17th September, 2016, 06:40 PM

Can I use this to understand all type of Eeprom like 93C56/C66/C76/C86 etc?

And this is 16bit (Sagem UCH Renault Clio 93C66x16)
ImageUploadedByTapatalk1471382559.180764.jpg[/QUOTE]

**megataso** · 18th September, 2016, 12:23 AM

Yes, pin 6 Org (organization off structure ).
Level HI or Low respective 16 bit or 8 bit

**Master8** · 19th February, 2025, 01:24 PM

Originally Posted by gjenkins0

Easy way to tell : read as 8 and the 16, save your files , try write 8bit back to eeprom and see if data has written same , if verify has success then it is 8 bit if you have errors then its 16 bit

buddy this not make sense to me.
is you write 8bit back , it will verify with 8bit read and not with 16bit
same way, if you write 16bit back, it will verify with 16bit and not with 8bit
Or maybe I have not understand your point ?