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CPU System Functions
Chapter 3
Preliminary User’s Manual U17566EE1V2UM00
3.3.1
Normal operation mode
Flash memory
devices
In normal operation mode, the internal flash memory is not re-programmed.
After reset release, the firmware acquires the user's reset vector from the flash
memory. The reset vector contains the start address of the user’s program
code. The firmware branches to that address. Program execution is started.
ROM mask devices
After reset release the user’s program is always started at address
0000 0000
H
.
3.3.2
Flash programming mode (flash memory devices only)
In flash programming mode, the internal flash memory is erased and
re-programmed.
After reset release, the firmware initiates loading of the user's program code
from the external flash programmer and programs the flash memory.
After detaching the external flash programmer, the microcontroller can be
started up with the new user's program in normal operation mode.
For more information see section
“Flash Memory“ on page 229
.
3.4 Address Space
In the following sections, the address space of the CPU is explained. Size and
addresses of CPU address space and physical address space are explained.
The address range of data space and program space together with their wrap-
around properties are presented.
3.4.1
CPU address space and physical address space
The CPU supports the following address space:
• 4 GB CPU address space
With the 32-bit general purpose registers, addresses for a 4 GB memory
can be generated. This is the maximum address space supported by the
CPU.
• 64 MB physical address space
The CPU provides 64 MB physical address space. That means that a
maximum of 64 MB internal or external memory can be accessed.
Any 32-bit address is translated to its corresponding physical address by
ignoring bits 31 to 26 of the address. Thus, 64 addresses point to the same
physical memory address. In other words, data at the physical address
0000 0000
H
can additionally be accessed by addresses 0400 0000
H
,
0800 0000
H
, …, F800 0000
H
, or FC00 0000
H
.
The 64 MB physical address space is seen as 64 images in the 4 GB CPU
address space:
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