Section: Interp SDK (3)
iportio - encapsulates all target-specific port I/O used by interp
int port_read( iword portaddr, iword count, iword buffaddr, int size );
int port_write( iword portaddr, iword count, iword buffaddr, int size);
These functions are the port I/O portability layer between interp and the hardware, or host operating system (if there is one.) In general terms, port I/O is communication between software and a device with a buffer that appears as one memory location (of a fixed size, such as byte or 32-bit word.) Writing data to this device is done by transfering each byte of data to the port memory location. Reading data from this device is done by transferring data from the port memory location into the next receiving buffer location.