The present invention discloses a selfcalibration method of a reading circuit of a nonvolatile memory, by which trimming data having recorded a
reference current are stored in a bit-pair form into the memory and regulate a
sense amplifier, and a value of the
reference current is obtained according to the trimming data when “0” and “1” in the outputted trimming data have the same quantities. The present invention further discloses a selfcalibration circuit of the nonvolatile memory, which includes a trimming data storage module, a
sense amplifier module, a logic judgment module, and a scanning module. The present invention furthermore discloses a nonvolatile memory circuit, which includes a
memory cell array and the selfcalibration circuit of the reading circuit of the nonvolatile memory. The present invention, not requiring an additional fuse or differential unit, can solve a
deadlock problem securely and reliably without increasing circuit area and test cost, and be widely applied to OTP, MTP and
EEPROM of various processes or various nonvolatile memories such as Flash
EEPROM, MRAM, and FeRAM, improving reliability of the memory effectively.