Method and system to identify and recover from faults in non-safety targets and safety targets

A system on a chip (SoC) comprising:

• an initiator;
• a safety target and a non-safety target;
• an interconnect fabric arranged to provide communication between the initiator and the safety target and the non-safety target;
• a first network interface unit (NIU) coupled to a network circuit and arranged to receive a first request from an initiator;
• determine that a response to the first request is not received in a response time from the safety target;
• and send a fault signal to a fault collection and control circuit (FCCC) indicative of the response to the first request from the initiator not being received within the response time;
• a second network interface unit (NIU) coupled to the network circuit and arranged to receive a second request from an initiator;
• determine that a response to the second request is not received in a response time from the non-safety target;
• and send a fault signal to the fault collection and control circuit (FCCC) indicative of the response to the second request from the initiator not being received within the response time;
• fence logic arranged between the interconnect fabric and the non-safety target to stop requests from the initiator from reaching the non-safety target based on the response not being received from the non-safety target;
• a dummy responder arranged to send to the initiator a response to the request that the non-safety target has not responded to, based on the response not being received from the non-safety target;
• and
• the fault collection and control circuit (FCCC) arranged to receive the fault signal from the first NIU or the second NIU;
• determine based on the fault signal a type of target from which the response is not received;
• reset only the non-safety target based on the response not being received from the non-safety target;
• and reset the safety target and the non-safety target based on the response not being received from the safety target,
• wherein the non-safety target is coupled to the second network interface unit, the safety target is coupled to the first network interface unit, the first network interface unit and the second network interface unit are coupled to the same network circuit of the interconnect fabric, the non-safety target and the safety target communicate with the same network circuit over separate communication paths, and the dummy responder is arranged on a communication path between the second network interface unit and the non-safety target.

A system on a chip (SoC) comprising:

• a plurality of initiators;
• a plurality of targets;
• a plurality of interconnect fabrics arranged to facilitate communication between at least one initiator and at least one target;
• wherein a plurality of first non-safety and first safety targets is coupled to a first interconnect fabric;
• second non-safety targets are only coupled to a second interconnect fabric;
• and a third interconnect fabric is coupled to the first interconnect fabric and the second interconnect fabric by a respective communication path;
• the third interconnect fabric further comprising a network interface unit (NIU) arranged to receive a communication from an initiator and provide a fault signal indicative of a fault detected to a fault collection and control circuit (FCCC) when a response to a request from the initiator is not received within a response time from one of the second non-safety targets;
• fence logic arranged between the third interconnect fabric and the second interconnect fabric to stop the communication from the initiator from reaching the second interconnect fabric over the communication path between the second interconnect fabric and third interconnect fabric when the fault is detected;
• and
• a dummy responder arranged between the third interconnect fabric and the second interconnect fabric to respond to the communication from the initiator when the one of the second non-safety targets does not respond and the fault is detected;
• wherein the FCCC is arranged to determine based on the fault signal a type of target from which the response is not received and reset only one or more of the second non-safety targets based on the response not being received from the one of the second non-safety targets, wherein the FCCC is further arranged to reset the first safety targets, the first non-safety targets, and the second non-safety targets based on another fault signal indicating that a response is not received from one of the first safety targets;
• wherein a first non-safety target of the plurality of first non-safety targets is coupled to a first network interface unit of the first interconnect fabric, a first safety target of the plurality of first safety targets is coupled to a second network interface unit of the first interconnect fabric, the first network interface unit of the first interconnect fabric and the second network interface unit of the first interconnect fabric is coupled to a same network circuit of the first interconnect fabric, and another dummy responder is arranged on a communication path between the first network interface unit of the first interconnect fabric and the first non-safety target coupled to the first network interface of the first interconnect fabric.