- MAX3421E has added 4 general purpose input pins and 4 general purpose output pins. The GPIO then has a total of 8 inputs and 8 outputs.
- MAX3421E has interrupt request function for each of the 8 general purpose input pins. Every pin has a corresponding interrupt enable bit and edge polarity bits.
- MAX3421E provides a SEPIRQ bit. The bit allows GPX pin to be used as a second interrupt output pin (aside from the INT pin). The interrupt is only used for GPIN interrupt.
- In edge interrupt mode, when an interrupt flag is cleared and another interrupt is in a suspended state, the MAX3421E can configure the time between when the INT pin is released and when there is the regeneration of a new interrupt signal. For the MAX3420E, this time interval is fixed at 10.6µs.