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Memory Type Specifiers

Memory Type Specifiers identify the memory areas, code banks, and SFR banks of 80x51 microcontrollers in debug commands. µVision provides predefined memory type specifiers. In addition, developers can create and address memory areas through user-defined memory type specifiers. Memory type specifiers are separated by a colon (:) from the memory address.

The table below shows the memory type specifiers and their availability for 80x51 microcontrollers.

Specifier 8051 251 51MX Description
D: available available available DATA; Internal, direct-addressable data memory.
I: available available available IDATA; Internal, indirect-addressable data memory.
X: available available available XDATA; External data memory.
C: available available available CODE; Code memory.
E:   available   Extended memory; Code and data memory.
Bn: available available   Code Banks; n is in the range [0..31].
Dn: available     SFR Banks; n is in the range [0..15].
available available   User-defined memory type specifiers. Memory areas of up to 64KB each can be defined. Use the debug command MAP to define the memory areas. The identifiers can be used to simulate external devices such as EEPROMs or LCDs. These memory areas cannot be addressed by the simulated CPU.

Memory type specifiers can be used in the following commands and debug functions: ASM, BreakAccess, BreakSet, Display, Enter, EVALuate, Go, MAP, PerofrmanceAnalyzer, SAVE, Unassemble, _RBYTE, _RDOUBLE, _RDWORD, _RFLOAT, _RWORD, _WBYTE, _WDOUBLE, _WDWORD, _WFLOAT, and _WWORD.


  • Examples can be found in the corresponding debug commands or debug functions.
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