I think IOL = IIL + (VIL/Rpd) where Rpd is only used to secure a correct voltage level while the port is not yet configured as output. Once a CMOS port is configured as output, Rpd is not needed. For the pull-up resistor on a N-channel port there are 2 considerations: - Is the resistor small enough so the rise time for switching from "L" to "H" is short enough? - Is the resistor big enough so the current on L-output of the port is not to high?
↧