Fetch operations in a disk drive control system

In a disk drive comprising a micro-controller, a micro-controller cache system in communication with the micro-controller and having a cache memory, a remote memory, and a buffer manager in communication with the micro-controller cache system and the remote memory, a method of providing data requested by the micro-controller comprising:

• sending a request for data from the micro-controller to the micro-controller cache system;
• determining whether the data request corresponds to data cached in the cache memory;
• determining whether the data request corresponds to an instruction code or non-instruction data;
• and
• if the data request corresponds to an instruction code that is not cached in the cache memory:
• fetching the instruction code from the remote memory via the buffer manager,
• filling the cache memory with the instruction code, and
• providing the cached instruction code to the micro-controller;
• and
• if the data request corresponds to non-instruction data that is not cached in the cache memory:
• fetching the non-instruction data from the remote memory via the buffer manager, and
• sending the non-instruction data uncached from the buffer manager to the micro-controller via the micro-controller cache system.