Abstract: Byte-swapping in a buffer memory system utilizes a byte-swapping register to avoid wasteful unused buffer memory spaces that may result from a data transfer of partial word data, i.e., bytes of data less than the number of bytes in a word, to the buffer memory. When a data transfer request, e.g., a write request, requires a transfer of a partial word, the partial request is written to a word in the buffer memory, and is also stored in the byte-swapping register. In a subsequent data transfer request, the partial word stored in the byte-swapping register is combined and concatenated with sufficient bytes of data of the subsequent data transfer request to produce a complete word. The complete word is written in the word in the buffer memory, replacing the previously stored partial word, and thus fills the previously unused buffer memory space.