Semiconductor device and temperature sensor system

Abstract

To suppress an increase in the number of voltage comparators with an expansion in a chip temperature detection range, a temperature sensor in a semiconductor device includes a temperature detection circuit for outputting a voltage according to the chip temperature, a reference voltage generating circuit for generating a plurality of reference voltages, and a plurality of voltage comparators for comparing each reference voltage obtained by the reference voltage generating circuit with an output voltage of the temperature detection circuit and thereby generating a chip temperature detection signal configured with multiple bits. Further, the temperature sensor includes a control circuit for controlling the reference voltages generated by the reference voltage generating circuit based on the chip temperature detection signal and thereby changing correspondence between the chip temperature detection signal and the chip temperature to shift a chip temperature detection range. It is possible to expand the chip temperature detection range by changing the correspondence between the chip temperature detection signal and the chip temperature, without increasing the number of voltage comparators.

1 - 11 . (canceled) 
     
     
         12 . A method for shifting a temperature detection range of a semiconductor chip, comprising:
 detecting a temperature of a semiconductor chip using a temperature sensor;   generating a voltage signal corresponding to the detected chip temperature;   generating a plurality of reference voltage signals;   comparing the plurality of reference voltage signals with the voltage signal corresponding to the detected chip temperature to thereby generate a chip temperature detection signal configured with multiple bits; and   shifting a temperature detection range of the chip by adjusting the plurality of reference voltages based on the chip temperature detection signal configured with multiple bits.   
     
     
         13 . The method of  claim 12 , wherein the adjusting is such that portions of the chip temperature detection range overlap each other around the shift of the chip temperature detection range. 
     
     
         14 . The method of  claim 12 , further comprising holding a reference voltage control signal for controlling the plurality of reference voltages in a first register, and holding the chip temperature detection signal with multiple bits in a second register prior to the adjusting. 
     
     
         15 . The method of  claim 14 , further comprising outputting the reference voltage control signal and the chip temperature detection signal with multiple bits outside of the temperature sensor, wherein the outputting is done using a third register. 
     
     
         16 . The method of  claim 14 , wherein the plurality of reference voltages are generated by dividing an input voltage using a plurality of resistors and selecting a resistor concerned in the division of the input voltage from among the plurality of resistors. 
     
     
         17 . The method of  claim 16 , wherein the selecting is based on the chip temperature detection signal with multiple bits held in the second register. 
     
     
         18 . The method of  claim 17 , wherein the selecting is done during a predetermined mask period. 
     
     
         19 . The method of  claim 18 , further comprising trimming an internal circuit of the chip based on the reference voltage control signal and the chip temperature detection signal with multiple bits. 
     
     
         20 . The method of  claim 19 , further comprising:
 generating a low-temperature operation signal based on the reference voltage control signal and the chip temperature detection signal with multiple bits; and   performing a dummy operation for generating heat in accordance with the low-temperature operation signal.   
     
     
         21 . The method of  claim 20 , further comprising:
 generating an interrupt signal based on the reference voltage control signal and the chip temperature detection signal with multiple bits; and   controlling an operation rate of a semiconductor device associated with the chip based on the interrupt signal.   
     
     
         22 . A system for shifting a temperature detecting range of a semiconductor chip in a semiconductor device, the system comprising:
 a temperature detection circuit for outputting a voltage signal according to a chip temperature detected by a temperature sensor;   a reference voltage generating circuit for generating a plurality of reference voltage signals;   a plurality of voltage comparators for comparing each reference voltage signal obtained by the reference voltage generating circuit with the voltage signal of the temperature detection circuit and thereby generating a chip temperature detection signal configured with multiple bits; and   a control circuit for controlling the reference voltage signals based on the chip temperature detection signal with multiple bits so as to shift a temperature detection range of the chip,   wherein the control circuit controls the reference voltages so that portions of the chip temperature detection range overlap each other around the shift of the chip temperature detection range.   
     
     
         23 . The system of  claim 22 , wherein the control circuit comprises:
 a first register for holding a reference voltage control signal for controlling the reference voltages; and   a second register for holding the chip temperature detection signal.   
     
     
         24 . The system of  claim 23 , wherein the control circuit comprises a third register for outputting the reference voltage control signal and the chip temperature detection signal to the outside of the temperature sensor. 
     
     
         25 . The system of  claim 24 , wherein the reference voltage generating circuit comprises:
 a plurality of resistors for dividing an input voltage; and   a switch for selecting a resistor concerned in the division of the input voltage from among the resistors.   
     
     
         26 . The system of  claim 25 , wherein the control circuit comprises a switch control circuit which increments or decrements a switch control signal for controlling an operation of the switch based on the chip temperature detection signal held in the second register. 
     
     
         27 . The system of  claim 26 , wherein the switch control circuit has a mask function for fixing a logic value of the signal sent from the second register only during a predetermined mask period, and increments or decrements the switch control signal during the mask period. 
     
     
         28 . The system of  claim 27 , wherein the module comprises a first module which receives the reference voltage control signal and the chip temperature detection signal through the third register and can trim an internal circuit of the system based on the reference voltage control signal and the chip temperature detection signal. 
     
     
         29 . The system of  claim 28 ,
 wherein the control circuit comprises a low-temperature operation signal generating circuit for generating a low-temperature operation signal based on the reference voltage control signal and the chip temperature detection signal, and   wherein the module comprises a second module which can perform a dummy operation for generating heat, in accordance with the low-temperature operation signal.   
     
     
         30 . The system of  claim 29 , wherein the module comprises a CPU which receives the reference voltage control signal and the chip temperature detection signal through the third register, generates a predetermined interrupt signal based on the reference voltage control signal and the chip temperature detection signal, and can perform control for decreasing an operation rate in the semiconductor device in accordance with the interrupt signal. 
     
     
         31 . The system of  claim 30 , wherein the temperature sensor comprises a reference voltage adjustment circuit for fine-adjusting the reference voltages generated by the reference voltage generating circuit in accordance with a signal provided from the outside of the temperature sensor.