Apparatus having cache memory disposed in a memory transaction path between interconnect circuitry and a non-volatile memory, and corresponding method

Abstract

A data processing system includes interconnect circuitry providing a plurality of memory transaction paths between one or more transaction masters, including a processor, debugging circuitry and a DMA unit, and one or more transaction slaves including a non-volatile memory, a DRAM memory and an I/O interface. A cache memory is provided between the interconnect circuitry and the non-volatile memory. This cache memory may be a two way set associative cache memory. The cache memory may serve as a read-only cache memory. A cache miss will result in a line fill of a cache line including the target data which was missed. If prefetching is enabled for the cache memory and the transaction was attempting to read a program instruction, then a prefetch operation may be performed in which a further contiguous cache line of data is also fetched into the cache memory upon the cache miss.