Flash Memory Structure - Analog Devices ADuCM355 Hardware Reference Manual

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FLASH MEMORY STRUCTURE

The memory pages are categorically divided into two sections: information space and user space. Total device storage is generally
described as the size of user space alone.
Information Space
Information space is reserved for use by Analog Devices and generally stores a bootloader (kernel), several trim and calibration values,
and other device specific metadata. All but the top 128 bytes of information space are readable by user code, but attempted erasures and
writes are denied. Bus errors are also generated if user code attempts to read the protected range of information space. Other read only
metadata can be made available to the user within the scope of the information space, but it is software defined. As such, the addresses
and data types are not defined by the flash controller.
Besides the top 128 bytes of protected space, the remainder of the information space is freely readable by user code. Information space
cannot be programmed or erased by the user, and these commands are denied. User code can perform a mass erase command on the
ADuCM355 without affecting the content of information space. This mass erase provides a mechanism to upload new user firmware and
data to a device without affecting the bootloader. User accessible information space is shown in Figure 51.
ADuCM355
INFORMATION SPACE
2kB
USER SPACE
128kB
Figure 50. ADuCM355 Flash Memory Structure
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