Embedded Design Handbook

ID 683689
Date 8/28/2023
Public
Document Table of Contents

7.5.2. Tradeoffs

There are design tradeoffs when using tightly coupled memory, including the following:

  • You must balance the benefits of more general speed enhancement provided by a cache, averaged over time, with the specific dedicated memory block consumed by a tightly coupled memory whose sole purpose is to make a single part of the code faster.
  • Software guarantees that performance-critical code or data is located in tightly coupled memory. That particular piece of code or data achieves high performance. Locating the code within tightly coupled memory eliminates cache overhead such as cache flushing, loading, or invalidating.
  • You must divide on-chip memory equitably to provide the best overall combination of tightly coupled instruction memory, tightly coupled data memory, instruction cache, and data cache.