I am trying to get data from a Holtek HT46R064B. I know that the Chip is an OTP (One-Time Programmable) Chip. I ask myself if it is possible to read some parts of its memory. In my case the chip is soldered to a PCB. I am trying to prove that the device it is installed in has a planned obsolescence programmed in.

I found this datasheet where they say

"The Program Memory is the location where the user code or program is stored. The device is supplied with One-Time Programmable, OTP, memory where users can program their application code into the device. By using the appropriate programming tools, OTP devices offer users the flexibility to freely develop their applications which may be useful during debug or for products requiring frequent upgrades or program changes."

Is it even possible to read any data from this chip?

  • \$\begingroup\$ why would you not post a link to the document on the Holtek website? \$\endgroup\$ – jsotola Jan 8 '18 at 20:31
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    \$\begingroup\$ "Is it possible" questions can usually be reduced to a better more specific question to make it easier for people to answer \$\endgroup\$ – Voltage Spike Jan 8 '18 at 21:18

Every (relatively recent) MCU (OTP and erasable) I've seen has at least an optional lock bit that prevents reading the memory. The information does not seem to be in the datasheet, so it's probably in another Holtek document. Assuming they had such functionality (and even if they didn't and there was any chance of competitors reverse-engineering) it would be crazy of them not to set their programming device to configure the protection bit to prevent reading. Normally the programming is performed, it is verified, then the memory is protected (forever in the case of an OTP, only allowing bulk erase in the case of reprogrammable).

However, the answer to your question is undoubtedly "yes". With some application of a suitable quantity of fungible assets such protection can always be broken. Maybe not by you, but someone can do it, using a variety of methods, some more invasive and expensive than others.

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    \$\begingroup\$ I like (and upvoted) your answer, but sometimes I feel like we need a close reason "Questions about whether someone might be able to achieve a certain technical feat are off-topic, as long as OP doesn't demonstrate necessary basic skills". But that's a B-priority compared to "questions about perpetuum mobiles" and "questions asking about random schematics copied from some website that OP doesn't even fundamentally understand". \$\endgroup\$ – Marcus Müller Jan 8 '18 at 20:39
  • \$\begingroup\$ @MarcusMüller Yes.. I agree and usually those questions get closed as "too broad" or something like that. It's sort of a technical question in this case- and maybe even a legitimate one if a class-action suit is brewing. \$\endgroup\$ – Spehro Pefhany Jan 8 '18 at 21:09

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