FAULT MONITORING CIRCUIT, SEMICONDUCTOR INTEGRATED CIRCUIT, AND FAULTY PART LOCATING METHOD
To provide a fault monitoring circuit capable of reliably transferring fault information to a circuit that maintains the system in the safe state and ensuring the safety as a system, a semiconductor integrated circuit, and a faulty part locating method. A fault monitoring circuit in accordance with an exemplary aspect of the invention obtains a fault signal output from a peripheral monitoring circuit 100 monitoring a peripheral circuit because of a fault in the peripheral circuit through a first path. Further, the fault monitoring circuit includes a fault signal output unit 12 that outputs the obtained fault signal to an external monitoring device. Furthermore, the fault monitoring circuit also includes a control unit 14 that obtains a fault signal output from the peripheral monitoring circuit 100 through a second path different from the first path, and controls an operation of a semiconductor integrated circuit based on the obtained fault signal.
1 . A fault monitoring circuit comprising:
a fault signal output unit that obtains a fault signal through a first path and outputs the fault signal to an external monitoring device, the fault signal being output from a peripheral monitoring circuit monitoring a peripheral circuit because of a fault in the peripheral circuit; and
a control unit that obtains a fault signal output from the peripheral monitoring circuit through a second path different from the first path, and controls an operation of a semiconductor integrated circuit based on the fault signal.
2 . The fault monitoring circuit according to claim 1 , further comprising a stop signal acquisition unit that obtains a stop signal output from the external monitoring device in response to a fault signal output from the fault signal output unit,
wherein an operation of a peripheral circuit in which the fault has occurred is stopped by a stop signal obtained by the stop signal acquisition unit.
3 . The fault monitoring circuit according to claim 1 , further comprising a pseudo-fault signal generation unit that generates a first pseudo-fault signal used to generate a fault in the peripheral circuit in a simulative manner, and outputs the first pseudo-fault signal to the fault signal output unit,
wherein the fault signal output unit outputs a fault signal to the external monitoring device based on the first pseudo-fault signal.
4 . The fault monitoring circuit according to claim 1 , further comprising a mask unit that determines whether or not a fault signal obtained by the fault signal output unit is output to the external monitoring device.
5 . The fault monitoring circuit according to claim 1 , wherein the control unit comprises a stop signal output unit that generates a stop signal used to stop an operation of a peripheral circuit in which the fault has occurred based on the fault signal, and output the stop signal.
6 . The fault monitoring circuit according to claim 1 , further comprising a fault storage unit that stores a fault state of the peripheral circuit specified based on a fault signal obtained by the control unit.
7 . A semiconductor integrated circuit comprising:
a peripheral monitoring circuit comprising a fault detection unit that detects a fault in a peripheral circuit;
a first fault signal output unit that obtains a fault signal through a first path and outputs the fault signal to an external monitoring device, the fault signal being output from a peripheral monitoring circuit that has detected a fault in the peripheral circuit;
a first control unit that obtains a fault signal through a second path different from the first path and controls an operation of the semiconductor integrated circuit based on the fault signal, the fault signal being output from a peripheral monitoring circuit that has detected a fault in the peripheral circuit;
a second fault signal output unit that obtains a fault signal through a third path different from the first and second paths and outputs the fault signal to an external monitoring device, the fault signal being output from a peripheral monitoring circuit that has detected a fault in the peripheral circuit;
a second control unit that obtains a fault signal through a fourth path different from the first, second and third paths and controls an operation of the semiconductor integrated circuit based on the fault signal, the fault signal being output from a peripheral monitoring circuit that has detected a fault in the peripheral circuit; and
a fault notification unit that, when a fault signal is output from at least one of the first and second fault signal output units, notifies a fault to an external monitoring device.
8 . The semiconductor integrated circuit according to claim 7 , further comprising a fault storage unit that stores a fault state of the peripheral circuit specified based on a fault signal obtained by the first and second control units.
9 . A faulty part locating method to locate a faulty part in a circuit comprising a plurality of peripheral circuits and a plurality of peripheral monitoring circuits monitoring the plurality of peripheral circuits, the faulty part locating method comprising:
outputting a pseudo-fault signal from the peripheral monitoring circuits, the pseudo-fault signal being used to generate a fault in the peripheral circuits in a simulative manner;
storing a fault state of the peripheral circuits based on the output pseudo-fault signal; and
locating a faulty part in the peripheral circuits, the peripheral monitoring circuits, and wiring lines connecting the peripheral circuits and the peripheral monitoring circuits based on a storage state of the fault state.