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I can't find really much about it online, but am curious if there is any bit-fiddling like tricks to verify all pins on a EEPROM are properly soldered/connected (particularly address pins on a parallel chip). I don't believe writing to a specific address and reading from the specific address would reveal any sort of error as within both functions a specific address pin would always be left low if disconnected (i.e. due to lack of solder, bridging, etc). I looked through the EEPROM documentation and there is no special routine in the chip to pull all address bits high to then check them all... is there any other way to check programmatically? Thanks.

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  • \$\begingroup\$ Testing RAM this way could be ok. You can use checksums, block markers as Daniel proposed, or just comparing contents to contents available in RAM. But using writes on EEPROM for testing purposes is wearing it out. In general, address problems will be seen when you power device on - it will just not work properly. But in general - please do a good work soldering devices well. If you do it manually, use head-mounted magnifier to examine the quality. Or do you have any real issue which needs to be solved? \$\endgroup\$
    – Anonymous
    Oct 4, 2016 at 20:13
  • \$\begingroup\$ Nope, no real issue... just a general curiosity for quality assurance. Thanks for the input! \$\endgroup\$
    – jparanich
    Oct 4, 2016 at 20:28

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Put a unique pattern at the start of every \$2^x\$ block before the EEPROM is installed. This should test your address and data pins if you plan it right.

Alternatively, you can write a value to each block start (one at a time), then read all other bytes for each test and see if it shows up somewhere else.

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  • \$\begingroup\$ Great advice, knew it would be something obvious... \$\endgroup\$
    – jparanich
    Oct 4, 2016 at 20:27
  • \$\begingroup\$ Just make sure you take into account any swapped address or data pins on your design. I commonly end up swapping some on parallel RAM interfaces just to ease the layout. \$\endgroup\$
    – SpaceCadet
    Oct 27, 2016 at 10:06

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