An on-chip testing unit can be implemented in an integrated circuit (e.g., a SoC) to validate the operation of cache memories associated with a processor of the integrated circuit. For each testing instruction to be executed by the processor for testing a cache memory, the testing unit can intercept information (e.g., address, data, and/or control signals) generated by the processor in response to executing the instruction. The testing unit can determine whether information generated by the processor matches corresponding expected information associated with the instruction. This can enable the testing unit to determine whether the processor can correctly identify an address from which the next instruction is to be fetched, can ensure consistency between data in the cache memories and persistent storage devices, and whether the processor is operating as expected. An error notification can be generated if the information generated by the processor does not match the expected information.