H/W to S/W Interfacing Techniques

The system is to be divided into some number of hardware and software blocks with appropriate means of interconnection.

The primary ways of connecting H/W to S/W are:

• CPU coprocessor and/or custom instructions,
• Packet channel connected as coprocessor or mapped to main register file,
• Programmed I/O to pin-level GPIO register,
• Programmed I/O to FIFOs,
• Interrupts (hardwired to one core or dynamically dispatched),
• Pseudo-DMA: processor generates addresses and device snoops data,
• DMA.