2.5.2.3 Behavior of Memory Accesses

The following table provides information about the behavior of accesses to each region in the memory map.

Table 2-11. Memory Access Behavior
Address range Memory region Memory Type1 XN1 Description
0x00000000- 0x1FFFFFFF Code Normal — Executable region for program code. You can also put data here.
0x20000000- 0x3FFFFFFF SRAM Normal — Executable region for data. You can also put code here. This region includes bit band and bit band alias areas, see Table 2-13.
0x40000000- 0x5FFFFFFF Peripheral Device XN This region includes bit band and bit band alias areas, see Table 2-14.
0x60000000- 0x9FFFFFFF External RAM Normal — Executable region for data.
0xA0000000- 0xDFFFFFFF External device Device XN External Device memory.
0xE0000000- 0xE00FFFFF Private Peripheral Bus Strongly- ordered XN This region includes the NVIC, System timer, and system control block.
0xE0100000- 0xFFFFFFFF Vendor specific Device XN Accesses to this region are to vendor-specific peripherals.
Note:
  1. See 2.5.2.1 Memory Regions, Types and Attributes for more information.

The Code, SRAM, and external RAM regions can hold programs. However, Arm recommends that programs always use the Code region. This is because the processor has separate buses that enable instruction fetches and data accesses to occur simultaneously.

The MPU can override the default memory access behavior described in this section. For more information, see 2.4.4 Memory Protection Unit.