A method of providing access to a multiplexed data bus having a plurality of data processing units coupled thereto. Each unit self-assigns sequence numbers thereto for identification purposes. The unit having the lowest sequence number obtains immediate access to the bus and may relinquish the bus by transmitting a control word, or token, with an incremented sequence number. All units receive the token but only the unit having the incremented sequence number gains access to the bus. The token passing continues through the series of sequence numbers and then recycles when no unit accepts the token (bus timeout). A newly added unit self-assigns a sequence number equal to the one transmitted prior to the bus timeout and thus acquires bus access on the next cycle. If a unit in the cycle fails, a bus timeout occurs mid-cycle and the access loop recycles. The units not gaining access to the bus during the cycle decrement their sequence numbers to close the gap, and hence gain access on the next cycle. The method allows for continuous system operation if units are added or deleted, without interrupting bus operation.
A system is provided for establishing a master-slave relationship at the physical layer between a first device and a second device in a peer-to-peer network. The system generates a first information which is associated with the first device. A second information is generated and associated with the second device. The first information is compared with the second information to generate a comparison result. Based on the comparison result, one device is designated as a master and the other device is designated as a slave.
An electronic timing control system for a glassware-forming machine includes a mini-computer master controller which controls the timing and sequence of operation of each of the individual section glassware-forming machine components. The master controller includes a plurality of control modules for section timing, conveyor motion, etc., each module of which outputs information to a corresponding serial multiplex I/O module. Each of the I/O modules connected to the master controller feeds data to a common data cable, according to a multiplexing scheme administered by the master controller. Data from the data cable is fed to each of the sections of the I.S. glassware forming machine, and particularly to a plurality of serially connected serial multiplexer modules. Each of the serial multiplexer modules corresponds to a section functional component operable to receive and form molten glass gobs into glassware articles. Each serial multiplexer module has a unique address. Information conveyed by the data cable includes a specific address for the module to which the data being transmitted is to be provided. Thus, although control data from the master controller is provided serially to all of the multiplexer I/O modules, only that module corresponding to an address transmitted by the controller is permitted to receive the data.
A method and apparatus of performing bus transactions on the external bus of the computer system. The present invention includes a method and apparatus for permitting out-of-order replies in a pipelined bus system. The out-of-order responses include the sending of tokens between both the requesting agents and the responding agents in the computer system without the use of dedicated token buses.
A method and apparatus of performing bus transactions on the bus of the computer system. The present invention includes a method and apparatus for permitting out-of-order replies in a pipelined bus system. The out-of-order responses include the sending of tokens between both the requesting agents and the responding agents in the computer system without the use of dedicated token buses.
A method and apparatus of performing bus transactions on the bus of the computer system. The present invention includes a method and apparatus for permitting out-of-order replies in a pipelined bus system. The out-of-order responses include the sending of tokens between both the requesting agents and the responding agents in the computer system without the use of dedicated token buses.
