Chapter 41General-Purpose Input/Output (GPIO)41.1 IntroductionNOTEFor the chip-specific implementation details of this module'sinstances see the chip configuration information.The general-purpose input and output (GPIO) module communicates to the processorcore via a zero wait state interface for maximum pin performance. The GPIO registerssupport 8-bit, 16-bit or 32-bit accesses.The GPIO data direction and output data registers control the direction and output data ofeach pin when the pin is configured for the GPIO function. The GPIO input data registerdisplays the logic value on each pin when the pin is configured for any digital function,provided the corresponding Port Control and Interrupt module for that pin is enabled.Efficient bit manipulation of the general-purpose outputs is supported through theaddition of set, clear, and toggle write-only registers for each port output data register.41.1.1 Features• Features of the GPIO module include:• Pin input data register visible in all digital pin-multiplexing modes• Pin output data register with corresponding set/clear/toggle registers• Pin data direction register• Zero wait state access to GPIO registers through IOPORTNOTEGPIO module is clocked by system clock.KL25 Sub-Family Reference Manual, Rev. 3, September 2012Freescale Semiconductor, Inc. 771
