Datasheet
19
4341H–MP3–10/07
AT8xC51SND2C/MP3B
6.1 ROM Memory Architecture
As shown in Figure 6-2 the AT83SND2C ROM memory is composed of one space detailed in
the following paragraph.
Figure 6-2. AT83SND2C Memory Architecture
6.1.1 User Space
This space is composed of a 64K Bytes ROM memory programmed during the manufacturing
process. It contains the user’s application code.
6.2 Flash Memory Architecture
As shown in Figure 6-3 the AT89C51SND2C Flash memory is composed of four spaces detailed
in the following paragraphs.
Figure 6-3. AT89C51SND2C Memory Architecture
6.2.1 User Space
This space is composed of a 64K Bytes Flash memory organized in 512 pages of 128 Bytes. It
contains the user’s application code.
This space can be read or written by both software and hardware modes.
6.2.2 Boot Space
This space is composed of a 4K Bytes Flash memory. It contains the boot loader for In-System
Programming and the routines for In Application Programming.
This space can only be read or written by hardware mode using a parallel programming tool.
FFFFh
64K Bytes
ROM Memory
0000h
User
FFFFh
64K Bytes
Flash Memory
0000h
Hardware Security
User
4K Bytes
Flash Memory
FFFFh
F000h
Boot
Extra Row