11.1. Cache terminology

In a von Neumann architecture, a single cache is used for instruction and data (a unified cache). A modified Harvard architecture has separate instruction and data buses and therefore there are two caches, an instruction cache (I-cache) and a data cache (D-cache). In the ARMv8 processors, there are distinct instruction and data L1 caches backed by a unified L2 cache.

The cache is required to hold an address, some data and some status information.

The following is a brief summary of some of the terms used and a diagram illustrating the fundamental structure of a cache:

Figure 11.2. Cache terminology

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