Temperature-based tamper detection

An apparatus, comprising:

• a trigger generator configured to output an enable signal;
• a first interface configured to receive a ready signal and an apparatus temperature;
• a timeout counter configured to:
• initiate a timer when the enable signal is output;
• and
• in response to the first interface not receiving, within a set time after the enable signal is output, at least one of the apparatus temperature and the ready signal, output a tamper event signal and a timeout event signal;
• a finite state machine (FSM) configured to:
• cause the trigger generator to output the enable signal;
• and
• in response to receiving the timeout event signal, cause the trigger generator to stop outputting the enable signal;
• an error code generator configured to:
• receive the tamper event signal when the tamper event signal is output;
• and
• generate an error code when the tamper event signal is output;
• and
• a second interface configured to:
• output a valid data signal and the apparatus temperature in the absence of receiving the error code from the error code generator and in response to a control signal received from the FSM;
• and
• in response to receiving the error code, output the valid data signal and the error code.

A method, comprising:

• asserting an enable signal to cause an integrated circuit (IC) to measure a device temperature;
• initiating, by a logic circuit of the device in response to transmission of the enable signal, a timer to run from the time that the enable signal is sent;
• determining, by the logic circuit, whether at least one of the device temperature and a ready signal indicating that the device temperature is available is received within a set time from a time at which the enable signal is asserted;
• in response to determining that neither the device temperature nor the enable signal is received within the set time, disabling the enable signal;
• and
• in response to determining that neither the device temperature nor the enable signal is received within the set time, outputting a tamper event signal and an error code, wherein the error code is indicative of a temperature outside of a device operating temperature range.