SYNCHRONIZING MESSAGES BEIWEEN THE MASTER AND A SLAVE PROCESSOR
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2002-Jan-08
In an environment with two or more microproces- this valid-msg-token. With all tasks in the master sors where there is a master and slave type of relation- processor, before the received message is processed, the ship, there is a potential for the two to get out of sync master processor compares and verifies the valid_msg due to the latency in the processing of the commands. -token with the valid_msg-token saved in its global This can cause the master processor to receive responses area. If the token in the messages match, then the that pertained to stale commands. associated messages are processed. (see Figure 1) To overcome this problem all TxAvtaster-Msgs This method of sending a randomly generated num- are sent from the master with a randomly or sequentially ber or a sequentially generated number has much less incremented number valid-msg-token. All Rx_ overhead in processing, both in ROM and in time as Master-Msgs are sent by the slave processors with compared to say time stamping.