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Help identifying unknown chip: ATMLH808 64C 1 P7H3561E

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So first a little background info. I've decided to hack my home cordless Panasonic DECT phone's ring tone. A friend also has a similar model phone by Panasonic and has decided to also try and hack his. The main DECT baseband chip is a SC144 mine is a SC14430 and his a SC14480. My phone stores its settings like phonebook in a separate 8pin SOIC I2C EEPROM by Microchip 24AA32AI-SN. So I've connected by Bus Pirate up and dumped my 4 KByte EEPROM and I have my phonebook and lots of other settings and unknown values. Excellent, so now we can commence hacking.

My friend on the other hand has a slightly different model and his settings are stored in some unknown chip. I can't find a datasheet or any other info about it. I for the moment can assume its a I2C EEPROM or Flash memory of at least the same size.

I think the initial letters ATML is short for Atmel. But I can't find similar part numbers on their site. I have attached a picture of his device. Any help in identifying what it is or even finding a datasheet would be appreciated.

May be a 24C64 or similar (24AA64 etc...)

Perhaps, but I'm still not convinced. I looked at the 24C64 data sheet it lists the pinout as follows: 1: A0, 2: A1, 3:A2, 4:GND, 5:SDA, 6:SCL, 7:WP, 8:VCC.

From the image I see C172 is the decoupling cap so we can assume pin 8 is indeed VCC. Pins 1 to 4 seem tyo be connected together so we can assume thats GND and the A0,A1,A2 pins are 0 the standard configuration. We could also go one step futher and assume R42,R41,R40 are the pull-ups for pins 5,6 and 7. So everything sounds good, but why do we have a pull-up on pin 7 which would be WP, this is normally tied to VCC or GND.. and even if the main processor was using that for write protection.. why the pull-up? perhaps so its write protected and then the processor pulls to GND when it chooses to write to the device? I suppose that's feasible.

I'll have my friend test it out and see if we can read the EEPROM. I'll post a response with details.

Page 15 (Part Marking Scheme section) - http://www.atmel.com/dyn/resources/prod_documents/doc5298.pdf

I had the same problem yesterday with ATMLU022 64C. :)

Thanks patb! Now thats exact confirmation. I now feel confident at hooking this up and not making it go bang ;)


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