Programmable system on a chip for temperature monitoring and control
View Patent ↗A programmable system-on-a-chip integrated circuit device includes a programmable logic block, at least one user non-volatile memory block, and temperature sensing and control analog and digital circuits on a single semiconductor integrated circuit chip or a flip chip, face-to-face, or other multiple die configuration. The programmable system-on-a-chip integrated circuit with temperature measuring and control circuitry performs temperature measurement and control functions and can be used to create an on-chip temperature log.
1. A programmable system-on-a-chip integrated circuit device comprising:
a programmable logic block;
a digital input/output circuit block;
a non-volatile memory block;
an analog input/output circuit block including, at least one junction temperature-sensing circuit comprising a diode connected transistor; and
a programmable interconnect architecture including programmable elements and interconnect conductors, ones of said programmable elements coupled to said programmable logic block, said non-volatile memory block, said analog input/output circuit block, said digital input/output circuit block, and to said interconnect conductors, such that inputs and outputs of said programmable logic block, said non-volatile memory block, said analog circuit block, said analog input/output circuit block, and said digital input/output circuit block can be programmably coupled to one another; and
temperature control logic for executing a temperature control method comprising:
switching current through the diode connected transistor from a first current level to a second current level;
measuring a difference in voltage across the diode between the first current level and the second current level,
converting the difference in voltage to a temperature, and
disabling cooling of the system-on-a-chip whenever the temperature does not exceed a first threshold.
2. The programmable system-on-a-chip integrated circuit device in claim 1 wherein:
the disabling of cooling of the system-on-a-chip comprises turning off a fan.
3. The programmable system-on-a-chip integrated circuit device in claim 1 wherein the temperature control method further comprises:
setting a pulse-width modulator duty cycle to a first level if the temperature is between the first threshold and a second threshold; and
setting the pulse-width modulator duty cycle to a second level if the temperature is between the second threshold and a third threshold.
4. The programmable system-on-a-chip integrated circuit device in claim 3 wherein the temperature control method further comprises:
setting the pulse-width modulator duty cycle to a third level if the temperature is between the third threshold and a fourth threshold.
5. The programmable system-on-a-chip integrated circuit device in claim 4 wherein:
the first threshold is approximately 40° C.;
the second threshold is approximately 70° C.;
the third threshold is approximately 100° C.; and
the fourth threshold is approximately 150° C.
6. The programmable system-on-a-chip integrated circuit device in claim 5 wherein:
the first level is 30%;
the second level is 60%; and
the third level is 90%.
7. The programmable system-on-a-chip integrated circuit device in claim 3 wherein the temperature control method further comprises:
shutting the system-on-a-chip down if the temperature exceeds the fourth threshold.
8. The programmable system-on-a-chip integrated circuit device in claim 1 wherein:
threshold values are stored in the non-volatile memory block.
9. The programmable system-on-a-chip integrated circuit device in claim 1 wherein:
the first current level is 1/10 the second current level.
10. The programmable system-on-a-chip integrated circuit device in claim 1 wherein:
the difference in voltage drop across the diode is equal to 59.6 m V at 25° C.
11. A method of monitoring temperature in a programmable system-on-a-chip integrated circuit device comprising:
powering up the system-on-a-chip;
calculating a temperature of the system-on-a-chip by a method comprising:
switching current through a diode connected transistor from a first current level to a second current level;
measuring a difference in voltage across the diode between the first current level and the second current level, and
converting the difference in voltage to a temperature; and
disabling cooling of the system-on-a-chip whenever the temperature does not exceed a first threshold;
repeating the calculating the temperature until the system-on-a-chip is shut down.
12. The method in claim 11 wherein:
the disabling of cooling of the system-on-a-chip comprises turning off a fan.
13. The method in claim 11 which further comprises:
setting a pulse-width modulator duty cycle to a first level if the temperature is between the first threshold and a second threshold; and
setting the pulse-width modulator duty cycle to a second level if the temperature is between the second threshold and a third threshold.
14. The method in claim 13 which further comprises:
setting the pulse-width modulator duty cycle to a third level if the temperature is between the third threshold and a fourth threshold.
15. The method in claim 14 wherein:
the first threshold is approximately 40° C.;
the second threshold is approximately 70° C.;
the third threshold is approximately 100° C.; and
the fourth threshold is approximately 150° C.
16. The method in claim 15 wherein:
the first level is 30%;
the second level is 60%; and
the third level is 90%.
17. The method in claim 13 which further comprises:
shutting the system-on-a-chip down if the temperature exceeds the fourth threshold.
18. The method in claim 11 which further comprises:
loading threshold values from a non-volatile memory.
19. The method in claim 11 wherein:
the first current level is 1/10 the second current level.
20. The method in claim 11 wherein:
the difference in voltage drop across the diode is equal to 59.6 m V at 25° C.