I'm trying to figure out how an OMRON Printer HEM PRT 1-Z operates (see related question on the Raspberry Pi StackExchange) in order to wire it to a Raspberry Pi Pico. Since I couldn't find any "service manual" or schematics diagram online, I'm having a look at the PCB and I'm trying to understand the underlying schematics. The PCB features various integrated circuits, one of them I couldn't identify.

Here's how it looks like:lousy photography of the unidentified IC

The shot is a bit blurry so here are the writings on it :

1323 HUL

(Additionally, any tips on how to determine the USB pinout are welcome)


1 Answer 1


That's a Toshiba 8-bit microcontroller. It does not have USB so USB pins do not go to this MCU.

  • \$\begingroup\$ Thanks! Do you know the reference for this microcontroller? I can't find anything for "Toshiba 1323 HUL"... How weird of it not having USB... The PCB clearly states "USB", and there isn't another microcontroller... \$\endgroup\$
    – corbin-c
    Jan 2, 2022 at 12:40
  • 1
    \$\begingroup\$ The chip name is CM29B, short for TMP86CM29B. The photo does not show anything about USB so post a better picture. If the product does have USB, there might be a separate USB chip. \$\endgroup\$
    – Justme
    Jan 2, 2022 at 12:58
  • \$\begingroup\$ Thanks again. Now that the chip is identified, I'm posting a new question about the USB matter, with better photos \$\endgroup\$
    – corbin-c
    Jan 2, 2022 at 13:03
  • \$\begingroup\$ Here's the separate question about USB pinout: electronics.stackexchange.com/q/602700/164864 \$\endgroup\$
    – corbin-c
    Jan 2, 2022 at 13:19

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