The size of the flash and RAM are purely chosen on the basis of current Digikey stock availabilities, and can be downgraded or upgraded as per specific needs. The HyperRAM uses an 8-bit bus, thus releasing more of the Propeller's smart I/O's to the outside world. All the Propeller's I/O are accessible from outside with 47 out of the 64 I/O lines completely free from any load. All I/O's are also reasonably length-matched within the module for ensuring correct operation of high-speed interfaces. There are several configuration pins that determine the module's behaviour and what is enabled on it.