The co-operative design methodology has significant advantages when used in safety-related systems. Coupled with the time-triggered architecture, the methodology can result in robust and predictable systems. Nevertheless, use of a co-operative design methodology may not always be appropriate especially when the system possesses tight resource and cost constraints. Under relaxed constraints, it might be possible to maintain a co-operative design by introducing additional software processing cores to the same chip. The resultant multi-core microcontroller then requires suitable design methodologies to ensure that the advantages of time-triggered co-operative design are maintained as far as possible. This paper explores the application of a time-triggered distributed-systems protocol, called “shared-clock”, on an eight-core microcontroller. The cores are connected in a mesh topology with no hardware broadcast capabilities and three implementations of the shared-clock protocol are examined. The custom multi-core system and the network interfaces used for the study are also described. The network interfaces share higher level serialising logic amongst channels, resulting in low hardware overhead when increasing the number of channels.