How to know if the data on the bus is a data or an instruction for an ARM Cortex-M0?

Question

I'm trying to implement a caching algorithm. But I want to cache only the Instructions, and not the data fetched from the memory(obviously). So how do I know that the data on the bus is a Data data or an Instruction data? I tried looking at the HPROT and HTRANS signals, but couldn't get any clarity

Answer 1

Figured it out HPROT[0] tells u if its a data or an opcode fetch