transient/permanent hardware fault detected via checking schemes (external reason). This isolation should be considered as a process and be “fine-tuned” by
minimizing the hardware loss.
Additionally, with energy saving in mind, the system could set up a simple
hardware configuration for particular task execution (internal reason). In
energy-saving functioning, reconfigurability has to provide a mechanism to disconnect or switch to a lower consumption mode all hardware elements that are not
required for the active program processes.
The term Syndrome is new Latin (origin 1535–45) and was originated from
Greek “Syndrome” where “Syn-” from combination, concurrence. For our purposes, a Syndrome is not just passive, i.e., presenting “a snapshot status” of a
system but also active, a serving tool to control the system configuration. For us, a
Syndrome is
a group of related or coincident things, events, actions, signs and symptoms that
characterize a particular abnormal condition.
A Syndrome also might help to answer the questions that have been omitted in
the vast majority of research on fault tolerance and performance: “what provides the
fault tolerance of the system?” and “how big a performance, reliability,
energy-saving gain might be achieved?”
It is usually assumed that the hardware core logic is ultrareliable and guarantees
control of configuration and reconfiguration. Unfortunately, using homogeneous
redundancy limits the reliability gain—since techniques based on the same type of
redundancy are vulnerable to the same threats. Hybrid techniques based on
heterogeneous redundancy can be more effective.
Thus, even when memory or processor checking schemes detect error and
transfer information to the Syndrome, this information might not be useful if the
system does not include either one or both: “External elements” responsible for
exercising reconfiguration and making decisions on configuration/reconfiguration.
Reconfiguration might be initiated externally, by other system elements to create
best fit for task configuration, or, if necessary, by “Internal elements” that are
capable to initiate the required sequence of reconfiguration for internal purposes and
reasons—faults, errors, or power saving.
Indeed, in regular computing systems, when there are faults in the processing
logic, to expect that it is able to perform self-healing and then control and monitor
the configuration of the rest of the system looks like a part of fairy tale, not
engineering.
There is a solution though, as described below. To be able to absorb any
trustworthy information about the status of system elements we have to aggregate
all checking and status signals about the condition of registers, memory, AU, and
LU as well as control unit. This aggregating scheme is implementation of a
Syndrome concept.
Clear, reconfigurability of different hardware areas passive where information is
stored, interfacing and active zones are different. Therefore, a scheme of implementation of reconfigurability should separate the passive zone and active zone of
the proposed architecture.
7.3 System Monitoring of Checking Process: A Syndrome
89
minimizing the hardware loss.
Additionally, with energy saving in mind, the system could set up a simple
hardware configuration for particular task execution (internal reason). In
energy-saving functioning, reconfigurability has to provide a mechanism to disconnect or switch to a lower consumption mode all hardware elements that are not
required for the active program processes.
The term Syndrome is new Latin (origin 1535–45) and was originated from
Greek “Syndrome” where “Syn-” from combination, concurrence. For our purposes, a Syndrome is not just passive, i.e., presenting “a snapshot status” of a
system but also active, a serving tool to control the system configuration. For us, a
Syndrome is
a group of related or coincident things, events, actions, signs and symptoms that
characterize a particular abnormal condition.
A Syndrome also might help to answer the questions that have been omitted in
the vast majority of research on fault tolerance and performance: “what provides the
fault tolerance of the system?” and “how big a performance, reliability,
energy-saving gain might be achieved?”
It is usually assumed that the hardware core logic is ultrareliable and guarantees
control of configuration and reconfiguration. Unfortunately, using homogeneous
redundancy limits the reliability gain—since techniques based on the same type of
redundancy are vulnerable to the same threats. Hybrid techniques based on
heterogeneous redundancy can be more effective.
Thus, even when memory or processor checking schemes detect error and
transfer information to the Syndrome, this information might not be useful if the
system does not include either one or both: “External elements” responsible for
exercising reconfiguration and making decisions on configuration/reconfiguration.
Reconfiguration might be initiated externally, by other system elements to create
best fit for task configuration, or, if necessary, by “Internal elements” that are
capable to initiate the required sequence of reconfiguration for internal purposes and
reasons—faults, errors, or power saving.
Indeed, in regular computing systems, when there are faults in the processing
logic, to expect that it is able to perform self-healing and then control and monitor
the configuration of the rest of the system looks like a part of fairy tale, not
engineering.
There is a solution though, as described below. To be able to absorb any
trustworthy information about the status of system elements we have to aggregate
all checking and status signals about the condition of registers, memory, AU, and
LU as well as control unit. This aggregating scheme is implementation of a
Syndrome concept.
Clear, reconfigurability of different hardware areas passive where information is
stored, interfacing and active zones are different. Therefore, a scheme of implementation of reconfigurability should separate the passive zone and active zone of
the proposed architecture.
7.3 System Monitoring of Checking Process: A Syndrome
89