This application relates to a memory management method for maximizing processing-in-memory (PIM) performance and reducing unnecessary DRAM access time. In one aspect, when processing a PIM instruction packet, an instruction processing unit secondarily processes a request for access to a destination address at which read and write actions of an internal memory are likely to be sequentially performed. By secondarily requesting the destination address, a row address of an open page of the internal memory may match a row address to which a PIM instruction packet processing result is written back. Also, the instruction processing unit inside the PIM maintains memory write and read addresses that have previously requested. The instruction processing unit compares the address of a packet to be processed to the maintained previous memory address and informs a memory controller about the comparison result through a page closing signal.