2.7.4.9.1 MPU Configuration for a Microcontroller
Usually, a microcontroller system has only a single processor and no caches. In such a system, program the MPU as indicated in the following table.
| Memory region | TEX | C | B | S | Memory type and attributes |
|---|---|---|---|---|---|
| Flash memory | b000 | 1 | 0 | 0 | Normal memory, Non-shareable, write-through |
| Internal SRAM | b000 | 1 | 0 | 1 | Normal memory, Shareable, write-through |
| External SRAM | b000 | 1 | 1 | 1 | Normal memory, Shareable, write-back, write-allocate |
| Peripherals | b000 | 0 | 1 | 1 | Device memory, Shareable |
In most microcontroller implementations, the shareability and cache policy attributes do not affect the system behavior. However, using these settings for the MPU regions can make the application code more portable. The values given are for typical situations. In special systems, such as multiprocessor designs or designs with a separate DMA engine, the shareability attribute might be important. In these cases refer to the recommendations of the memory device manufacturer.