Selects a memory zone, see C-SPY memory zones.

Specify the start address for the memory address range, in hexadecimal notation.

Specify the end address for the memory address range, in hexadecimal notation.

When the target CPU is not executing, all read accesses from memory are loaded into the cache. For example, if two Memory windows show the same part of memory, the actual memory is only read once from the hardware to update both windows. If you modify memory from a C-SPY window, your data is written to cache only. Before any target execution, even stepping a single machine instruction, the RAM cache is flushed so that all modified bytes are written to the memory on your hardware.

This memory is assumed not to change during a debug session. Any code within such a range that is downloaded when you start a debug session (or technically, any such code that is part of the application being debugged) is stored in the cache and remains there. Other parts of such ranges are loaded into the cache from memory on demand, but are then kept during the debug session. Note that C-SPY will not allow you to modify such memory from C-SPY windows.

Even though flash memory is normally used as a fixed read-only memory, there are applications that modify parts of flash memory at runtime. For example, some part of flash memory might be used for a file system or simply to store non-volatile information. To reflect this in C-SPY, you should choose the RAM cache type for those instead. Then C-SPY will assume that those parts can change at any time during execution.

A range of this type is completely uncached. All read or write commands from a C-SPY window will access the hardware immediately. Typically, this type is useful for special function registers, which can have all sorts of unusual behavior, such as having different values at every read access. This can in turn have side-effects on other registers when they are written, not containing the same value as was previously written, etc.