I've been going through this datasheet and I don't understand what is meant by 'OTP' for selection the function of the GPIO pins. The function select table can be found on page 20. I'm also confused why it refers to inputs and ouputs as CMOS and NMOS. Can someone explain this?

  • \$\begingroup\$ I'm going to presume OTP in this context is One Time Programming as opposed to Over Temperature Protection. How Ricoh implements it though I am unsure. \$\endgroup\$ – JYelton Aug 29 '16 at 20:38
  • \$\begingroup\$ @JYelton it does have I2C, maybe it uses that? But I guess that wouldn't make it 'one time programming' \$\endgroup\$ – jack sexton Aug 29 '16 at 20:42
  • \$\begingroup\$ Maybe OTP is used to set the power-on defaults and the I2C can then change those settings if needed? \$\endgroup\$ – Majenko Aug 29 '16 at 22:16

They're not referring to CMOS or NMOS, the options are CMOS or N-Channel open-drain.
The CMOS option can push or pull the pin up or down, while the open-drain option can only pull the pin down (relying on an external pull-up resistor).

OTP is almost certainly referring to One-Time-Programming.
There doesn't seem to be any indication in that document on how this programming is done though.

  • \$\begingroup\$ do you know how to do one time programming? \$\endgroup\$ – jack sexton Aug 29 '16 at 20:47
  • \$\begingroup\$ My guess is that the OTP is only done at the manufacturer. So you need to check which version of the IC you have. From the table, there should be somewhere in the part number you ordered to tell you how the GPIOs are configured at the factory \$\endgroup\$ – Daniel V Aug 29 '16 at 22:26

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