摘要:
Receiver for receiving a data stream via a data bus, which receiver samples the bits of the data stream in an over-sampling process, in which n bit strobe offsets are used and n data sets with i bits are sampled,—applies a decision criterion for identifying those data sets with correct bit values. This decision uses checksum CRC,—selects one of the identified data sets with correct bit values and—uses the bit strobe offset, which was used for receiving the selected data streams, for receiving the data stream. In this way the multiphase clock with optimal phase shifts is selected.
摘要:
The invention relates to a method of transmitting user data via a communications medium (2) between subscribers (3) connected to the communications medium (2), wherein the data are transmitted in recurrent cycles (8) and at least one slot (9, 10) in each cycle (8) is intended for the user data of at least one subscriber (3). In order to permit a particularly efficient data transmission via the communications medium (2) at least one of the slots (10) is used to transmit the user data of different subscribers (3) (A, C, F) in different cycles (8). In addition, a bus guardian (6) of one subscriber (3) determines whether the subscriber (3) may transmit user data in the current slot (9, 10) of the current cycle (8), the bus guardian (6) having at least indirect access to a universal condition available throughout the entire communications system (1). In particular, an internal counter of the bus guardian (6) is synchronized to a universal cycle counter.
摘要:
The invention refers to one of a number of nodes of a communication system. The nodes are connected to a communication media for transmitting data among the nodes. Said one node comprises a communication controller, across which the node is connected to the communication media, and a bus guardian for controlling access of the communication controller to the communication media. In order to provide a cheap but nevertheless reliable way for monitoring the synchronized clock signal of a node of a communication system and in particular for detecting deviations of the synchronized clock signal it is suggested that a synchronized clock signal from the communication controller is made available to the bus guardian, and that the bus guardian comprises means for monitoring the synchronized clock signal using a bus guardian internal clock signal, which is generated by means of an electronic circuit and which is less accurate than the synchronized clock signal to be monitored.
摘要:
In order to carry out in a communication system (1) a temporal synchronization of clocks in a particularly rapid and efficient manner, a method is proposed which has the following steps: acquiring state values which are dependent on a time base (10); filing each acquired state value at a position in a first list L comprising (k+1) positions, if the acquired state value is smaller than or equal to the (k+1) smallest element of the list L, where k is a predefinable error tolerance; filing the acquired state value at a position in a second list H comprising (k+1) positions, if the acquired state value is greater than or equal to the (k+1) greatest element of the list H; forming a mean value from the (k+1) smallest element of the list L and the (k+1) greatest element of the list H, if the number of acquired state values is greater than or equal to (2k+2); determining a correction value as a function of the mean value; and correcting a current state value of the clocks that are to be synchronized.
摘要:
A dual-channel network with in each case one communication controller (2, 6) for each of the two channels (A, B). In order to ensure that the two channels (A, B) operate on a temporally matched basis, an exchange of current states (“ready, “abort”) takes place via an external or an on-chip interface (1a, 1b). The cold start operation is carried out only if, and so long as, both communication controllers are in the “ready” state.