Network co-processor for vehicles

A network processor (1), comprising:

• a master processor (13) and a network coprocessor (4) which is coupled to network nodes;
• a first bus system (30), associated essentially with the master processor (13) and also serving to couple the network coprocessor (40) to the master processor(13);
• a second bus system (35), associated essentially with the network coprocessor and also serving to couple the individual network nodes (10) to the network coprocessor;
• a first network memory (20), having an area for first layer messages (DLL) which is associated with the second bus system (35) and which contains the messages to be read or written for the associated network nodes (10);
• a second network memory (21), having an area for second layer messages (HL) which contains the information serving to convert the first layer messages to be read or written, said second network memory (21) being associated either
• with the first system (30), in which case a first direct memory access device (50) between the second and first bus systems (35, 30) permits direct and, thus, rapid access by the network coprocessor (40) to the second network memory (21),
• or
• with the second bus system (35), in which case a second direct memory access device (50.1) between the first and second bus systems (30, 35) permits direct and, thus, rapid access by the master processor to the second network memory.