Methods and arrangements to interface memory are described. Many embodiments comprise comparing a transaction or access from a source to memory addresses associated with the source to determine whether an address associated with the transaction is accessible by the source. Some embodiments may comprise defining protected memory. Several embodiments may comprise defining protected memory by, for example, determining a configuration for memory. Such embodiments may comprise protecting a memory location or limiting access to memory addresses associated with a protected memory location. Some of these embodiments may comprise accessing registers to define protected memory and verifying accesses to a memory location according to the definition of protected memory. Further embodiments may comprise generating an association between a source of an access and a memory location and storing the association to facilitate access to the memory location by the source.