The memory comprises a first pass gate transistor, a second pass gate transistor, a third pass gate transistor, and a fourth pass gate transistor. On-resistance of the second pass gate transistor is smaller than that of the first pass gate transistor, so that first read current flowing from a first read/write port of a first group of read/write dual ports is equal to second read current flowing from a second read/write port of the first group of read/write dual port. On-resistance of the fourth pass gate transistor is smaller than that of the third pass gate transistor, so that third read current flowing from a first read/write port of a second group of read/write dual ports is equal to fourth read current flowing from a second read/write port of the second group of read/write dual port.