3.2.1 AHB-Lite slave interface memory map

The AHB‑Lite slave interface can access 4MB of memory space where the contents of the 4MB, or smaller, embedded Flash can be read. The embedded Flash can have an extra extended memory range that can be reachable on the upper 2MB of the given 4MB address range.

The size of access is fixed at 0b100. Therefore, all wrapping boundaries must be calculated based on the wrap size and the access size having a total value of 4 for 128‑bit accesses. The hsize[2:0] signal indicates access size. See A.1 AHB-Lite slave interface signals.

The following figure is an example that uses 1MB of large Flash with 4KB page size and two Extension pages. The example shows how the embedded Flash space can be reached through different routes.

Figure 3-1 AHB-Lite slave interface memory map
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In the figure:

  • * Indicates that access rights depend on the properties of extension pages that the process‑specific part handles. GFC-100 supports both read and write, or erase.
  • ** Indicates that aliasing might occur if the process‑specific part maps the same addresses multiple times within the 2MB address space of the main area, or the 2MB address space of the extended area.

The example memory map has 256 pages in the main memory area. GFC-100 maps 4MB of address space from the system memory to the GFB address range. The first 1MB is mapped to the embedded Flash main area directly, the second 1MB is reserved. The extended memory area has 8KB of space that is mapped to the extended memory area from the third 1MB. The last 1MB is reserved.

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