A memory controller includes logic circuitry to generate a first data address identifying a location in a first external memory array for storing first data, a first tag address identifying a location in a second external memory array for storing a first tag, a second data address identifying a location in the second external memory array for storing second data, and a second tag address identifying a location in the first external memory array for storing a second tag. The memory controller includes an interface that transfers the first data address and the first tag address for a first set of memory operations in the first and the second external memory arrays. The interface transfers the second data address and the second tag address for a second set of memory operations in the first and the second external memory arrays.