User`s guide

AT85C51SND3Bx Firmware User’s Guide 4-15
7691A–MP3–08/07
Section 4
Code & Data Management
4.1 Principle The SND3 chip permits:
 to customise the memory organisation
 to use a code swap feature (= code banking)
 to store a large constant data in the NandFlash
Reminder: The C51 core use different memory space (code, data, xdata). The size of
data space is 256B. The size of code space is limited at 64KB and xdata space is limited
at 64KB.
4.1.1 Custom memory
organisation
The AT85C51SND3B chip uses a 64KB of RAM to store the data and code, this particu-
larity permits to configure the memory size according to your needs.
4.1.1.1 Rules xdata space size + code space size = 64KB – 512B
code space size = code common size + code bank size*