The LM8328 GenI/O - Expander and Keypad Controller is a dedicated device to unburden a host processor from scanning a matrix-addressed keypad and to provide flexible and general purpose, host programmable input/output functions. Three independent PWM timer outputs are provided for dynamic LED brightness modulation.
It communicates with a host processor through an I2C-compatible ACCESS.bus serial interface. It can communicate in Standard (100 kHz) - and Fast-Mode (400 kHz) in slave Mode only.
All available input/output pins can alternately be used as an input or an output in a keypad matrix or as a host programmable general purpose input or output.
Any pin programmed as an input can also sense hardware interrupts. The interrupt polarity (“high to low” or “low to high” transition) is thereby programmable.
The LM8328 follows a predefined register based set of commands. Upon start-up (power - on) a configuration file must be sent from the host to setup the hardware of the device.