Patent Application
20060168378
The present invention relates to a method of addressing and/or activating at least one user that is associated with at least one serial data bus, in particular at least one C[ontroller] A[rea] N[etwork] bus, and is intended to carry out at least one application.
The present invention further relates to a chip unit, particularly a system chip unit, for addressing and/or activating at least one user that is associated with at least one serial data bus, in particular at least one C[ontroller] A[rea] N[etwork] bus, and is intended to carry out at least one application.
As complexity increases in serial networking, particularly in automobiles, so too is there a greater and greater increase in the energy required by the electronic components used in the serial networking. Added to this is the fact that more and more functions aimed at providing comfort and convenience are active even when the motor vehicle is parked and then have to be operated directly from the vehicle's battery.
Because a large number of functions are serially networked via for example the C[ontroller] A[rea] N[etwork] bus, it is always the entire bus system that is activated even when there are only a few vehicle functions operating, due to the fact that each user on the bus is “woken up” or “kept awake” by the transmission of data by these few users. This causes a current consumption by the system that is undesirably high and, given that only a few vehicle functions are operating, one that is even quite unnecessary.
In the prior art, there are now known methods in which all the users are first woken up by a global wake-up. After this, as many users as desired can be changed back to the sleeping state, from which they can only be woken again by means of a separately defined waking symbol or by means of a special level scheme.
Something that is disadvantageous in this case however is that all the nodes have to be woken up first before a subnetwork is set up by switching off the ones that are not required. At least for a short time this causes a high current consumption, which is a great nuisance, particularly with cyclic wake-up processes.
In another method, each data packet on the bus is analyzed by special hardware to allow a decision to be made as to whether the message is relevant to a sleeping, and thus switched-off, node. Only if the comparison of the message in question with a predefined message is successful is the application woken up and started. One of the things that is disadvantageous in this case however is that a second bus protocol controller, which has a continuous power supply, is required to monitor the bus, using a complex filter for the messages, and to search it for relevant messages.
The system chip B analyzes the data traffic on the serial CAN bus A by means of a CAN transceiver B.1 and by means of its own CAN controller (including a quartz oscillator) B.2, whereas the application microcontroller (including a quartz oscillator) C.2 and the application hardware D can be switched off to save current on the system.
However, a second application CAN controller C.1 is required in this case and this needs to operate very accurately (which is why a separate quartz oscillator and a separate CAN controller are required) so that incorrect decisions will not be made as a result of the sort of faults that typically occur in automobiles. If the message comparator B.3 has found the predefined wake-up message, the application D is activated and supplied with current. However, an implementation of this complicated kind is generally very expensive.
Taking the disadvantages and shortcomings described above as a point of departure and with due allowance for the prior art outlined, it is an object of the present invention so to further develop a method of the kind detailed in the first paragraph and a chip unit of the kind detailed in the second paragraph that individual users on the network, that is to say individual users on the data bus, can be selectively woken in a targeted manner, in order in this way to be able to form individual subnetworks as and when required without having to wake up the entire network.
This object is achieved by a method having the features specified in claim 1 and by a chip unit having the features specified in claim 8. Advantageous embodiments and useful refinements of the present invention are described in the respective sets of dependent claims.
The present invention is thus based on the principle of subnetwork operation by selective waking. It is possible in this case, under the teaching of the present invention, to avoid the duplication of the protocol controller hardware that is mandatory in the prior art by using the protocol controller (hereinafter also referred to as protocol controller unit) that is already present in the application controller (hereinafter also referred to as application controller unit) and providing it with a partial supply from the system chip or some other item of hardware only when there is traffic present on the serial data bus system at the time. For the exchange of signals between the system chip and the application controller, use is made in this case of the connections that are present anyway, and there is thus no further external burden that has to be operated.
With regard to the procedure followed in the method according to the present invention, the voltage supply to the protocol controller is provided by at least one upstream transceiver (hereinafter also referred to as transceiver unit) or by the system chip (hereinbefore and hereinafter also referred to as chip unit or system chip unit) whenever messages occur on the data bus (the term “messages” is intended in this case to cover not only messages but also communications and/or data packets occurring on the data bus).
A fact that has an advantageous effect in this case is that the protocol controller may, on a C[ontroller] A[rea] N[etwork] basis for example, be separately supplied within the application by following a system. The protocol controller itself may form a stand-alone device or may be incorporated in the microcontroller.
In a particularly inventive embodiment, the separately supplied protocol controller, which may usefully have a clock signal of its own suited to the requirements that exist, may compare the incoming messages that occur with stored reference messages, with at least one message filtering unit being available within the protocol controller for the purposes of this comparison of messages.
The protocol controller only sends an acknowledgement to the upstream transceiver or the upstream system chip if the comparison proves positive. Only in the event of a suitably positive acknowledgement of this kind from the protocol controller does the upstream transceiver or the upstream system chip then provide the application and its microcontroller with a supply.
The present invention further relates to a transceiver unit for carrying out the method of the type described above. The transceiver unit is connected to the databus and is in communication with the protocol controller unit and with the application controller unit.
According to a preferred further development of the present invention, at least one control logic is associated with the transceiver unit and/or at least one control logic is implemented in the transceiver unit.
The present invention further relates to a first voltage regulator which is connected to at least one battery unit and which is in communication with at least one transceiver unit, in particular of the type described above, which voltage regulator is intended to supply a voltage to at least one protocol controller unit, which is associated with at least one user provided for carrying out at least one application, in the event of at least one incoming message that occurs on at least one serial databus, in particular on at least one C[ontroller]A[rea]N[etwork] bus.
The present invention further relates to a second voltage regulator which is connected to at least one battery unit and which is in communication with at least one transceiver unit, in particular of the type described above, which second voltage regulator is intended to supply a voltage to at least one application controller unit, which is associated with at least one user provided for carrying out at least one application, in the event of a correspondence and/or match between at least one incoming message that occurs on at least one serial databus, in particular on at least one C[ontroller]A[rea]N[etwork] bus, and at least one reference message stored in at least one protocol controller unit and associated with the application.
The chip unit, in particular system chip unit, in accordance with the present invention comprises
The present invention further relates to a protocol controller unit for comparing at least one incoming message which occurs on at least one databus with at least one stored reference message which is associated with at least one application to be carried out by at least one user, in particular by means of a message comparator and/or message filter of the type described above. In the event of one or more incoming messages, the protocol controller unit must be first supplied with a voltage.
According to a preferred further development of the present invention, the protocol controller unit comprises at least one timing generator, in particular a quartz unit, which enables the protocol controller unit to usefully have timing of its own, in particular quartz timing.
The present invention further relates to an application controller unit of the type described above. The application controller unit is to be supplied with a voltage only in the event of a correspondence and/or match between at least one incoming message that occurs on at least one databus and at least one stored reference message associated with at least one application to be carried out by at least one user.
According to a preferred further development of the present invention, the application controller unit may be activated by at least one transceiver unit, in particular of the type described above.
The present invention further relates to a user of the type describes above, which is provided to carry out at least one application and which is associated with at least one databus, comprising
The present invention further relates to a system of the type described above, comprising
Finally, the present invention relates to the use of a method of the kind described above and/or of at least one chip unit of the kind described above for addressing and/or activating at least one user in automobile electronics and particularly in the electronics of motor vehicles that is associated with at least one data bus and is intended to carry out at least one application.
As has already been described above, there are various possible ways in which the teaching of the present invention may advantageously be embodied and refined. On the one hand, reference can be made in this connection to the claims dependent on claims 1, 4, 9 and 11, and on the other, further aspects, features and advantages of the present invention are apparent from and will be elucidated with reference to the illustrative embodiment shown in
In the drawings:
Shown diagrammatically in
If messages traffic arises and is detected on the CAN data-bus line 10, a transceiver 34 that is connected to the data bus 10 and fitted with control logic, or the system chip unit 30 that contains the transceiver unit 34, to which transceiver 34 or system chip unit 30 there is a permanent supply from a battery unit 20, switches on a first voltage regulator 32 that is connected to the transceiver unit 34 by connections 92, 94 and whose purpose is to supply current to a protocol controller unit 42 that is associated with the application user 40 and that has a clock signal of its own that is suited to requirements. For this purpose, the first voltage regulator 32 is connected to the battery unit 20.
Via a receive line (=RXD line 52), which connects the transceiver unit 34 and the protocol controller unit 42 together, the bit stream is passed on to the protocol controller unit 42, where it is analyzed. In the protocol controller unit 42, there then takes place, by means of a message comparator or message filter, a comparison of the received messages or data packets with stored reference messages or data packets.
Because of the availability of the quartz-controlled clock signal (from the quartz oscillator unit in the protocol controller unit 42) and of the protocol hardware, the detection of certain messages or data packets can take place with great accuracy. However, because there is not as yet any supply to the application itself, including the application microcontroller 44, there is a considerable saving of current in this case.
If the result of the comparison is positive, the protocol controller unit 42 transmits a feedback signal to the transceiver unit 34, i.e. to the system chip unit 30, via a transmission line (=TXD connection 54). A second voltage regulator 36, which, via a feed line 26, is likewise connected to the battery unit 20 and which is connected to the transceiver unit 34 by a connection 96, is then switched on and the application is fully started via the connecting line 82 as a result of voltage being supplied from the second voltage regulator 36 to the application controller unit 44 associated with the user 40. As can also be seen from what is shown in
If, on the other hand, no message is detected, this is to say if the incoming message from the CAN bus 10 does not correspond to any of the reference messages associated with the application that are stored in the protocol controller unit 42, then the second voltage regulator 36 is not switched on.
Once there has been a quiescent state on the bus for a period of time that is preset in the system chip unit 30 or in the transceiver unit 34, the first voltage regulator 32 is switched off as well and current is saved to the maximum extent in this way. The system chip unit 30 or the transceiver unit 34 now draws its supply only from the battery unit 20 and waits for incoming messages from the CAN data bus 10 so that it can then switch the first voltage regulator 32 back on again.
The system 100 can be configured and controlled via a mode control interface 70 between the transceiver unit 34 (or the system chip unit 30) and the application controller unit 44.
One further point that should be made in connection with the embodiment that has been elucidated by reference to
So, to sum up, it can be said that the system 100 shown in
For this purpose, the protocol controller unit 42 is advantageously used within the application for the addressing/activation analysis of the bit stream that is flowing. A separate current supply scheme for the protocol controller unit 42 and for the application controller unit 44 allows a significant reduction to be achieved in this case in the current consumption of the system 100.
A simple “handshake” mechanism between the physical connection to the data bus 10 and the serial protocol controller unit 42 is used to make the decision as to whether or not the local system is to wake up, that is to say is to be addressed and activated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102 25 578.4 | Jun 2002 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB03/02115 | 6/5/2003 | WO | 7/11/2005 |
