Expandable slave device system

A bus system comprising:

• a global bus comprising uni-directional signal lines, the global bus having global bus sections each section including a first end and a second end;
• a master device transmitting data to one global bus section and receiving data from another global bus section;
• first and second global bus terminators coupled to the first and second ends of a last global bus section;
• a plurality of macrosystems including a first and a last macrosystem, each macrosystem including:
• one or more subsystems connected in parallel to each other and to the master device via the global bus, each subsystem including:
• a local bus;
• one or more slave devices coupled to the local bus;
• a write buffer that receives incoming signals from the master device via the global bus and transmits the incoming signals to the one or more slave devices via the local bus;
• and
• a read buffer that receives outgoing signals from the one or more slave devices via the local bus and transmits the outgoing signals to the master device via the global bus;
• and
• a plurality of global bus transceivers connecting global bus sections, each pair of global bus sections being coupled to at least one macrosystem.