Instruction fetch unit

The Instruction Fetch Unit pre-fetches and aligns incoming instructions from the 64-bit wide Program Memory Interface (PMI). Instructions are placed in predicted program order in the Issue unit (FIFO).

The Instruction Protection Unit checks the validity of accesses to the PMI and the integrity of incoming instructions fetched from the PMI.

The branch unit (Prefetch) examines the fetched instructions for branch conditions and predicts the most likely execution path based on previous branch behavior. The Program Counter Unit (PC) is responsible for updating the program counter.

Figure 1. Instruction fetch unit