Flexible time-triggered protocol for CAN: new scheduling and dispatching solutions

conferenceObject

Fonseca, J.
Martins, E.
Almeida, L.
Pedreiras, P.
Neves, P.A.C.S.

FONSECA, J. [et al.] – Flexible time-triggered protocol for CAN: new scheduling and dispatching solutions. In International CAN Conference, 7, Amsterdão, Outubro 2000. ICC’00. p. 1-8

Flexible time-triggered protocol for CAN: new scheduling and dispatching solutions

CAN - Controller Area Network
FPGA - Field Programmable Gate Arrays

2011-03-10T12:00:23Z
2011-03-10T12:00:23Z
2000-10

One of the possibilities to build robust communication systems with respect to their temporal behaviour is to use autonomous control based on the time-triggered paradigm. The FTT-CAN - flexible time-triggered protocol, relies on centralised scheduling but makes use of the CAN native distributed arbitration to reduce communication overhead. There, a planning scheduler is used within a master node to reduce the scheduling run-time overhead. On-line changes to the communication requirements can then be made under guaranteed timeliness. In addition FTT-CAN also allows an efficient combination of both time-triggered and event- triggered traffic with temporal isolation. In this paper, recent evolutions of the initial protocol definition concerning transmission of synchronous and asynchronous messages are presented. These consist in a time division of the elementary transmission window which optimises the available bandwidth for asynchronous messages, keeping the timeliness of synchronous messages without jeopardising their transmission jitter. A novel solution for the planning scheduler is also presented. It consists in an FPGA-based coprocessor which implements the planning scheduler technique without imposing overhead to the arbiter CPU. With it, it is possible to reduce strongly the plan duration thus allowing on-line admission demanded by system elements and, also, to extend the protocol application to high-speed networks.

openAccess

eng