The real-time requirements of microprocessor interfaces lie in the range of mere microseconds, if not nanoseconds. Conventional microprocessors are largely operated using a high-level operating system (HLOS), such as Embedded Linux or Windows Embedded CE. However, this makes it very difficult to achieve a deterministic reaction time of less than one millisecond in the user application or kernel driver. The Texas Instruments AM1808 ARM microprocessor offers an alternative solution. This paper describes a method that integrates the real-time requirements of an interface back into the microprocessor, without needing an ASIC or FPGA.