Time sensitive transaction over an asynchronous serial link
A method of controlling data transmission from a transmitting unit to a receiving unit through an asynchronous serial link is provided. The method is performed by a controlling unit and includes the steps of sequentially receiving data and synchronization messages are sequentially received from the transmitting unit; sequentially parsing the messages received; and when a message parsed is a synchronization message, blocking relaying to the receiving unit, of the data messages following said synchronization message, until an event associated with the synchronization message occurs.
1. A method of controlling data transmission from a transmitting unit to a receiving unit, through an asynchronous serial link, the method comprising the following steps, performed by a controlling unit:
sequentially receiving data messages and synchronization messages from the transmitting unit,
sequentially parsing the messages received, and
when a message parsed is a synchronization message, blocking relaying to the receiving unit, of the data messages following said synchronization message, until an event associated with the synchronization message occurs,
wherein:
when a data message is preceded by a synchronization message, the data message is delivered to the receiving unit when the event associated with the synchronization message occurs, and
when a data message is not preceded by a synchronization message, the data message is delivered immediately after reception, without checking; or waiting for an event associated with the synchronization message to occur.
2. A method according to claim 1 , wherein the event is an expiration of a timer defined in the synchronization message.
3. A method according to claim 2 , wherein the timer is clocked on the basis of the cycles of a communication channel, said cycles defining time periods for transmitting the messages through said communication channel.
4. A method according to claim 1 , wherein the event is at least one of:
the receipt of a message by the controlling unit through the communication channel,
the receipt of a message by the controlling unit though a communication channel different from the communication channel through which are transmitted the data messages and the synchronization messages,
the receipt of a given number of messages by the controlling unit though one or more communication channels, and
the receipt of a message generated by the receiving unit.
5. A method according to claim 1 , further comprising queuing the messages received in a FIFO (First In First Out) buffer, and wherein blocking relaying of the data messages comprises stopping reading the FIFO buffer.
6. A method according to claim 5 , wherein reading of the FIFO buffer is restarted after the event occurs.
7. A method according to claim 1 , wherein the synchronization message contains an identification of the event.
8. A controlling unit for controlling data transmission from a transmitting unit to a receiving unit, through an asynchronous serial link, the controlling unit comprising:
a communication unit configured for sequentially receiving data messages and synchronization messages from the transmitting unit,
a processing unit for sequentially parsing the messages received, and, when a message parsed is a synchronization message, for blocking relaying to the receiving unit, of the data messages following said synchronization message, until an event associated with the synchronization message occurs,
wherein:
when a data message is preceded by a synchronization message, the data message is delivered to the receiving unit when the event associated with the synchronization message occurs, and
when a data message is not preceded by a synchronization message, the data message is delivered immediately after reception, without checking or waiting for an event associated with the synchronization message to occur.
9. A controlling unit according to claim 8 , wherein the processing unit is further configured for setting a timer when the event is an expiration of a timer defined in the synchronization message.
10. A controlling unit according to claim 9 , wherein the processing unit is further configured for clocking the timer on the basis of the cycles of a communication channel, said cycles defining time periods for transmitting the messages through said communication channel.
11. A controlling unit according to claim 8 , wherein the event is at least one of:
the receipt of a message by the controlling unit through the communication channel,
the receipt of a message by the controlling unit though a communication channel different from the communication channel through which are transmitted the data messages and the synchronization messages,
the receipt of a given number of messages by the controlling unit though one or more communication channels, and
the receipt of a message generated by the receiving unit.
12. A controlling unit according to claim 8 , further comprising a FIFO (First In First Out) buffer, and wherein the processing unit is further configured for queuing the messages received in said buffer and wherein blocking relaying of the data messages comprises stopping reading the FIFO buffer.
13. A controlling unit according to claim 12 , wherein reading of the FIFO buffer is restarted after the event occurs.