SEMICONDUCTOR DEVICE, METHOD FOR CONTROLLING THE SAME, AND SEMICONDUCTOR SYSTEM

摘要

The semiconductor device includes a temperature sensor controlled so that temperature measurement is made once at each of a plurality of different reference temperatures at an interval of a preset number of times of refresh operations and a plurality of latch circuits holding the results of temperature measurement. A refresh period is set from outputs of the latch circuits inclusive of the result of temperature measurement carried out last time for each of a plurality of different reference temperatures. After start of measurement, temperature measurements are repeated every wait time corresponding to circulation of the refresh operations. The refresh period is set such that the high-temperature side results of temperature measurement are prioritized (FIG. 2).

主权项

1. A dynamic random access memory comprising:
a memory cell array; a temperature measurement circuit providing a first temperature measurement output having a first level to indicate a temperature lower than a first predetermined temperature and a second level to indicate a temperature higher than the first predetermined temperature, the temperature measurement circuit comprising;
a temperature sensor device;a resistor string having a plurality of taps;a first trimming circuit having a first plurality of transistors connected to the plurality of taps; a first latch circuit for providing the first temperature measurement output; anda self-refresh control circuit refreshing the memory cell array with a first refresh frequency while the first temperature measurement output has the first level and refreshing the memory cell array with a second refresh frequency higher than the first refresh frequency while the first temperature measurement output has the second level, wherein the first plurality of transistors are controlled to improve the accuracy of the first temperature measurement output.