Semiconductor device having variable parameter selection based on temperature and test method
A semiconductor device that may include temperature sensing circuits is disclosed. The temperature sensing circuits may be used to control various parameters, such as internal regulated supply voltages, internal refresh frequency, or a word line low voltage. In this way, operating specifications of a semiconductor device at worst case temperatures may be met without compromising performance at normal operating temperatures. Each temperature sensing circuit may include a selectable temperature threshold value as well as a selectable temperature hysteresis value. In this way, temperature performance characteristics may be finely tuned. Furthermore, a method of testing the temperature sensing circuits is disclosed in which a current value may be monitored and temperature threshold values and temperature hysteresis values may be thereby determined.
1. An apparatus comprising:
a temperature-sensing circuit;
a first register coupled to and separate from the temperature-sensing circuit and configured to:
receive a temperature select value from a register load operation; and
provide the temperature select value to the temperature-sensing circuit; and
a second register coupled to the temperature-sensing circuit and configured to provide a hysteresis select value to the temperature-sensing circuit.
2. The apparatus of claim 1 , wherein the first register and the second register are both register circuits.
3. The apparatus of claim 1 , wherein the first register is configured to receive a plurality of temperature select values from a plurality of first register load operations and the second register is configured to receive a plurality of temperature select values from a plurality of second register load operations.
4. The apparatus of claim 1 , wherein the temperature-sensing circuit is configured to provide a temperature indication signal.
5. The apparatus of claim 1 , wherein the hysteresis select value is a difference between a current temperature value and a previous temperature value.
6. The apparatus of claim 1 , further comprising an array voltage generator that receives the temperature select value from the temperature-sensing circuit.
7. The apparatus of claim 1 , wherein the first register and the second register have a default setting upon power up.
8. The apparatus of claim 1 , wherein the temperature-sensing circuit includes a variable resistor, and wherein the temperature-sensing circuit is configured to modify a resistance value of the variable resistor based on the temperature select value.
9. A method comprising:
receiving, from a first register, a temperature select value from a register load operation;
providing, from the first register, the temperature select value to a temperature-sensing circuit separate from the first register, wherein the temperature-sensing circuit includes a temperature threshold value; and
providing, from a second register, a hysteresis select value to the temperature-sensing circuit, wherein the temperature-sensing circuit further includes a temperature hysteresis value.
10. The method of claim 9 , wherein the first and second registers are both register circuits.
11. The method of claim 9 , further comprising receiving, at the first register, a plurality of temperature select values from a plurality of first register load operations, and at the second register, a plurality of temperature select values from a plurality of second register load operations.
12. The method of claim 9 , further comprising providing, from the temperature-sensing circuit, a temperature indication signal.
13. The method of claim 9 , further comprising calculating the hysteresis select from a difference between a current temperature value and a previous temperature value.
14. The method of claim 9 , wherein the first register and the second register have a default setting upon power up.
15. The method of claim 9 , wherein the temperature-sensing circuit includes a variable resistor, the method further comprising modifying, by the temperature-sensing circuit, a resistance value of the variable resistor based on the temperature select value.
16. A method comprising:
receiving, at a plurality of register circuits, a plurality of bits corresponding to a plurality of temperature select values from a plurality of register load operations;
providing, from the plurality of register circuits, the plurality of bits to a temperature-sensing circuit that is separate from the plurality of register circuits, wherein the temperature-sensing circuit includes a temperature threshold value; and
providing, from one of the plurality of register circuits, a hysteresis select value to the temperature-sensing circuit, wherein the temperature-sensing circuit further includes a temperature hysteresis value.
17. The method of claim 16 , further comprising providing, from the temperature-sensing circuit, a temperature indication signal.
18. The method of claim 16 , further comprising calculating the hysteresis select from a difference between a current temperature value and a previous temperature value.
19. The method of claim 16 , wherein the first register and the second register have a default setting upon power up.
20. The method of claim 16 , wherein the temperature-sensing circuit includes a variable resistor, the method further comprising modifying, by the temperature-sensing circuit, a resistance value of the variable resistor based on the temperature select value.