Arduino Due -- 96KB or 100KB?

Arduino Due spec says it has a SAM3X8E microcontroller and 96KB SRAM: https://www.arduino.cc/en/Main/ArduinoBoardDue

SAM3X8E spec says that it has 100KB of SRAM: http://www.atmel.com/images/atmel-11057-32-bit-cortex-m3-microcontroller-sam3x-sam3a_datasheet.pdf#page=32

So can the 4KB of NFC SRAM of SAM3X8E somehow be used with Arduino IDE?

SRAM0 and SRAM1 are in the bit band region. The bit band alias region is mapped from 0x2200 0000 to 0x23FF FFFF.

The NAND Flash Controller (NFC) embeds 4224 bytes of internal SRAM. If the NFC is not used, these 4224 Kbytes can be used as general-purpose SRAM. It can be seen at address 0x2010 0000.

Hermann.

It is possible to map it and use it. But, it is not contiguous to the 96k of RAM so things stored in there will have to fit within just that space. Additionally, you'd have to either edit the link script or otherwise target variables to the 4kb space manually. Personally it seems like something I wouldn't bother with. In most cases 96k should be sufficient and the extra 4k is not going to magically save the project. It might be better to rethink the rest of the code to shave enough RAM usage off to fit into just the 96k.