The LM8333 Mobile I/O Companion offloads the burden of keyboard scanning from the host, while providing extremely low power consumption in both operational and standby modes. It supports keypad matrices up to 8 x 8 in size (plus another 8 special-function keys), for portable applications such as cellphones, PDAs, games, and other handheld applications. Key press and release events are encoded into a byte format and loaded into a FIFO buffer for retrieval by the host processor. An interrupt output (IRQ) is used to signal events such as keypad activity, a state change on either of two interruptcapable general-purpose I/O pins, or an error condition. Interrupt and error codes are available to the host by reading dedicated registers.