An apparatus for convolution operations is provided. The apparatus includes a PE array, a datastore, writing modules, reading modules, and a controlling module. The PE array performs MAC operations. The datastore includes databanks, each of which stores data to be used by a column of the PE array. The writing modules transfer data from a memory to the datastore. The reading modules transfer data from the datastore to the PE array. Each reading module may transfer data to a particular column of the PE array. The controlling module can determine the rounds of a convolution operation. Each round includes MAC operations based on a weight. The controlling module controls the writing modules and reading modules so that the same data in a databank can be reused in multiple rounds. For different rounds, the controlling module can provide a reading module accesses to different databanks.