There are many common applications that require a microcontroller to interface to an externally clocked parallel bus. Examples include CMOS image sensors, tuner ICs, DSP ports, and high speed parallel ADCs. Supporting these with a standard MCU is difficult due to several reasons: external Interrupt-driven parallel data transfer may be too slow, a typical DMA triggered by external clock may not be fast enough, and standard external memory bus interfaces do not support external asynchronous clock. The Parallel Capture Mode in the PIO Controller simplifies the design and performance of such systems. Microchip's PIO Controller has a Parallel Capture Mode. The Capture Mode consists of an 8-bit data bus, two data enable lines, and a clock input.