On-die thermal management for VLSI applications
Apparatus and methods are provided for managing operations of a semiconductor chip. In an exemplary embodiment, there is provided a semiconductor chip that may comprise a temperature sensor, a thermal heater, a processor and thermal control logic. The thermal control logic may be configured to: determine that a first temperature read-out from the temperature sensor reaches a first temperature threshold value, turn on the thermal heater, determine that a second temperature read-out from the temperature sensor reaches a second temperature threshold value that is lower than the first temperature threshold value, suspend functions of the processor, determine that a third temperature read-out from the temperature sensor reaches the first temperature threshold value, resume the functions of the processor, determine that a fourth temperature read-out from the temperature sensor reaches a third temperature threshold value that is higher than the first temperature threshold value and turn off the thermal heater.
1. A semiconductor chip, comprising:
a temperature sensor;
a thermal heater;
a processor; and
thermal control logic comprising circuitry configured to:
determine that a first temperature read-out from the temperature sensor reaches a first temperature threshold value;
turn on the thermal heater;
determine that a second temperature read-out from the temperature sensor reaches a second temperature threshold value that is lower than the first temperature threshold value;
suspend functions of the processor;
determine that a third temperature read-out from the temperature sensor reaches the first temperature threshold value;
resume the functions of the processor;
determine that a fourth temperature read-out from the temperature sensor reaches a third temperature threshold value that is higher than the first temperature threshold value; and
turn off the thermal heater.
2. The semiconductor chip of claim 1 , wherein the thermal control logic is configured to suspend the functions of the processor by asserting a signal to the processor and resume the functions of the processor by de-asserting the signal to the processor.
3. The semiconductor chip of claim 2 , wherein the signal is asserted to a logic low to suspend the functions of the processor.
4. The semiconductor chip of claim 1 , wherein the thermal heater comprises a switch and a resistive structure, and the thermal control logic is configured to turn on the thermal heater by asserting a control signal to the switch to turn on the switch and turn off the thermal heater by de-asserting the control signal to the switch to turn off the switch.
5. The semiconductor chip of claim 4 , wherein the resistive structure is a forward biased diode and the switch is a NMOS, and the forward biased diode's biased voltage is controlled by the NMOS.
6. The semiconductor chip of claim 5 , wherein the thermal heater is one of a plurality of thermal heaters evenly placed on a die of the semiconductor chip.
7. The semiconductor chip of claim 1 , wherein the first temperature threshold value, the second temperature threshold value and the third temperature threshold value are programmable by firmware.
8. The semiconductor chip of claim 1 , further comprising a memory and an input/output whose functions are also suspended when the functions of the processor is suspended.
9. The semiconductor chip of claim 1 , wherein the thermal control logic is further configured to send a plurality of control signals to the temperature sensor to configurate and calibrate the temperature sensor.
10. The semiconductor chip of claim 1 , wherein the processor is configured to configure the thermal control logic by sending control and command signals to the thermal control logic.
11. A method of operating a semiconductor chip, comprising:
determining that a first temperature read-out from a temperature sensor on the semiconductor chip reaches a first temperature threshold value;
turning on a thermal heater on the semiconductor chip;
determining that a second temperature read-out from the temperature sensor reaches a second temperature threshold value that is lower than the first temperature threshold value;
suspending functions of a processor on the semiconductor chip;
determine that a third temperature read-out from the temperature sensor reaches the first temperature threshold value;
resuming the functions of the processor;
determining that a fourth temperature read-out from the temperature sensor reaches a third temperature threshold value that is higher than the first temperature threshold value; and
turning off the thermal heater.
12. The method of claim 11 , wherein suspending the functions of the processor comprises asserting a signal to the processor and resuming the functions of the processor comprises de-asserting the signal to the processor.
13. The method of claim 12 , wherein the signal is asserted to a logic low to suspend the functions of the processor.
14. The method of claim 11 , wherein the thermal heater comprises a switch and a resistive structure, and turning on the thermal heater comprises asserting a control signal to the switch to turn on the switch and turning off the thermal heater comprises de-asserting the control signal to the switch to turn off the switch.
15. The method of claim 14 , wherein the resistive structure is a forward biased diode and the switch is a NMOS, and the forward biased diode's biased voltage is controlled by the NMOS.
16. The method of claim 15 , wherein the thermal heater is one of a plurality of thermal heaters evenly placed on a die of the semiconductor chip.
17. The method of claim 11 , wherein the first temperature threshold value, the second temperature threshold value and the third temperature threshold value are programmable by firmware.
18. The method of claim 11 , wherein the semiconductor chip further comprises a memory and an input/output whose functions are also suspended when the functions of the processor is suspended.
19. The method of claim 11 , further comprising sending a plurality of control signals to the temperature sensor to configurate and calibrate the temperature sensor.
20. The method of claim 11 , further comprising configuring thermal control logic by sending control and command signals from the processor to the thermal control logic.