Row hammer refresh address calculation method and calculation circuit, and semiconductor memory device mounting the calculation circuit

A row hammer refresh address calculation circuit for calculating row hammer refresh addresses, comprising:

• a calculation unit, configured to calculate, in a memory array that has a plurality of memory cells arranged in rows and columns, an upper-side adjacent row hammer refresh address (RHA) and a lower-side adjacent RHA using a first operation or a second operation, and to calculate an upper-side further-adjacent RHA and a lower-side further-adjacent RHA by a third operation or a fourth operation, wherein the second operation performs more operations than the first operation, and the fourth operation performs more operations than the third operation;
• and
• a control unit, configured to control operations of the calculation unit, and when the seed address is refreshed, an address obtained in the first operation is used as a prioritized adjacent RHA and is calculated first by the first operation, and an address obtained in the third operation is used as a prioritized further-adjacent RHA and is calculated first by the third operation,
• wherein the upper-side adjacent RHA corresponds to an upper-side adjacent word line that corresponds to a word line allocated to a seed address, and the lower-side adjacent RHA corresponds to a lower-side adjacent word line that corresponds to the word line allocated to the seed address;
• wherein the upper-side further-adjacent RHA corresponds to an upper-side further-adjacent word line that corresponds to the word line allocated to the seed address, and the lower-side further-adjacent RHA corresponds to a lower-side further-adjacent word line that corresponds to the word line allocated to the seed address;
• and
• wherein the address obtained in the first operation is from the upper-side adjacent RHA and the lower-side adjacent RHA corresponding to the refreshed seed address, and the address obtained in the third operation is from the upper-side further-adjacent RHA and the lower-side further-adjacent RHA corresponding to the refreshed seed address.