Abstract: An integrated circuit comprising a plurality of functional modules and interconnected via a packet router for conveying request and response packets is described. Transactions involve the dispatch of request packets and receipt of corresponding response packets. Each packet conveys a number of transaction attributes which can control how the packet is managed by control circuitry which controls the flow of packets on the packet router. For example the transaction attributes can include a transaction number, a grouping indicator, a priority indicator and a post indicator.

Abstract: Connection ports for interconnecting functional modules in an integrated circuit are described. The connection ports provide enhanced functionality based around a common port primitive. This simplifies port design and selection and also allows a common packet protocol to be used for communication of packets across the packet router. In particular, there is improved functionality of target ports which allow out of order requests to be dealt with and out of order responses to be generated.

Abstract: A pipelined arbitration mechanism allows a routing control decision to be effected for a later packet while a current packet is being transferred. The later packet can be issued a fixed number of cycles after the current request. The mechanism has particular advantages when used with a plurality of functional modules connected to a packet router, whereby a single functional module can generate a current request relating to a current packet and a deferred arbitration request relating to a later packet to be issued a fixed number of cycles after the current request.

Abstract: Connection ports for interconnecting functional modules in an integrated circuit are described. The connection ports provide enhanced functionality based around a common port primitive. This simplifies port design and selection and also allows a common packet protocol to be used for communication of packets across the packet router. In particular, there is improved functionality of target ports which allow out of order requests to be dealt with and out of order responses to be generated.

Abstract: A pipelined arbitration mechanism allows a routing control decision to be effected for a later packet while a current packet is being transferred. The later packet can be issued a fixed number of cycles after the current request. The mechanism has particular advantages when used with a plurality of functional modules connected to a packet router, whereby a single functional module can generate a current request relating to a current packet and a deferred arbitration request relating to a later packet to be issued a fixed number of cycles after the current request.

Abstract: The implementation of transactions on an integrated circuit comprising a plurality of functional modules connected to a packet router is described. Each functional module generates request packets for implementing memory access operations, each request packet having an operation field comprising eight bits of which a packet type bit denotes the type of the packet, four operation family bit denote the function to be implemented by the packet and three operation qualifier bits act to qualify the function.

Abstract: The invention relates to monitoring error conditions in an integrated circuit. The integrated circuit has a packet router to which a plurality of functional modules are connected between which packets are transmitted. Each functional module is associated with an error monitoring register for monitoring error conditions. The error monitoring register contains a plurality of error flags which can be set when a particular error condition is detected. The invention particularly but not exclusively relates to the setting of communication error flags relating to errors in communication of the packet.

Abstract: An integrated circuit which has a packet router to which a plurality of functional modules are connected by respective ports is described. One of the ports acts as a socket port for an expansion socket. The expansion socket provides a plurality of additional expansion ports to which additional functional modules can optionally be connected. All the ports connected to the packet router, including the expansion socket port, preferably lie in a common address space for the integrated circuit.

Abstract: In a system comprising an interconnect and a plurality of modules connected to the interconnect, a circuit for controlling which of said modules is able to put information onto said interconnect, said circuit comprising a store which stores status information for each module, said status information defining if the respective module is permitted to put information on said interconnect.

Abstract: A circuit for use in a system comprising a plurality of modules connected to an interconnect, said modules being arranged to put information onto said interconnect, said circuit comprising circuitry for determining if information on the interconnect satisfies one or more conditions; and circuitry for storing at least part of the information which satisfies the one or more conditions.