8051 Instruction Set ManualArchitecture Overview Memory Classes and Layout Classic 8051 Classic 8051 Memory Layout Extended 8051 Variants Extended 8051 Memory Layout NXP 80C51MX NXP 80C51MX Memory Layout 251 Architecture 251 Memory Layout CPU Registers 8051 Variants 251 Architecture Program Status Word (PSW) Opcodes Instructions
Extended 8051 Memory Layout
The extended 8051 8051 architecture includes the following memory classes.
BIT, DATA, and IDATA
The BIT, DATA, and IDATA memory classes comprise the on-chip memory of the 8051 architecture and are shown in the following figure.
CODE, ECODE, and Memory Banks
The CODE and ECODE
memory classes are typically stored in ROM that may be either
off-chip or on-chip. The CODE memory class may be used for
program code and refers to the first 64K (or Bank 0) of this
read-only memory area.
XDATA and HDATA
The XDATA memory class refers
to the first 64K of RAM which may be off-chip or on-chip.
of your data.