Systems and methods for managing cache replacement

A processing system comprising:

• a microcontroller device;
• an external memory device external to the microcontroller device, the external memory device coupled to the microcontroller device;
• the microcontroller device including:
• bus masters configured to execute application codes;
• a random access memory (RAM) device internal to the microcontroller device and coupled to the bus masters via an interconnect, the RAM device including a system memory portion and an instruction portion, the instruction portion configured to store copies of a subset of load units from the external memory device for use by the application codes, wherein the load units include executable instructions and/or data, and are associated with a corresponding one of the application codes;
• a cache controller device coupled to the random access memory and the external memory device and including load entity queues, each of the load entity queues is associated with one of the bus masters, the cache controller device configured to:
• manage a set of eviction candidates which includes
• i) selection of further eviction candidates to include in the set of eviction candidates, and
• ii) removal of a first eviction candidate selected from the set of eviction candidates for replacement with a copy of a requested load unit;
• select based on a controllable selection rate a second eviction candidate from the copies of the load units in the instruction portion to include in the set of eviction candidates;
• discard the first eviction candidate or second eviction candidate if at least one of the load entity queues vetoes the first eviction candidate or the second eviction candidate where the veto is arranged to occur at one or more of
• i) before addition of the second eviction candidate to the set of eviction candidates, and
• ii) before replacement of the first eviction candidate selected from the set of eviction candidates with the copy of a requested load unit;
• and
• replace the first eviction candidate selected from the set of eviction candidates in the instruction portion with the copy of the requested load unit stored in the external memory in response to selecting the first eviction candidate from the set of eviction candidates.