BETAAddress registers
The I²C host selects a register before exchanging data.
16-bit register-controlled I²C port expander
MCP23017 Internal Circuitry
Explore the internal circuitry and functional stages of MCP23017.
Package view
Inside MCP23017
Register-controlled ports with direction, latches and event capture.
Explore the circuit
Select a stage to see its role and connections
Control ports
IODIR, OLAT and GPPU define direction, driven value and weak pull-ups.
Capture changes
Interrupt logic records selected input events and exposes flags and captured values.