DOC4106 datasheet(14/47 Pages) ATMEL

14 / 47 page

AT8xC51SND1C

4106F–8051–10/02

Address Spaces

The AT8xC51SND1C derivatives implement four different address spaces:

•

Program/Code Memory

•

Boot Memory

•

Data Memory

•

Special Function Registers (SFRs)

Code Memory

The AT89C51SND1C and AT83C51SND1C implement 64K Bytes of on-chip pro-

gram/code memory. The AT83C51SND1C product provides the internal program/code

memory in ROM technology while the AT89C51SND1C product provides it in Flash

technology.

The Flash memory increases ROM functionality by enabling in-circuit electrical erasure

and programming. Thanks to the internal charge pump, the high voltage needed for pro-

gramming or erasing Flash cells is generated on-chip using the standard VDD voltage.

Thus, the AT89C51SND1C can be programmed using only one voltage and allows in

application software programming commonly known as IAP. Hardware programming

mode is also available using specific programming tools.

Boot Memory

The AT89C51SND1C implements 4K Bytes of on-chip boot memory provided in Flash

technology. This boot memory is delivered programmed with a standard bootloader soft-

ware allowing In-system Programming commonly known as ISP. It also contains some

Application Programming Interfaces routines commonly known as API allowing user to

develop his own bootloader.

Data Memory

The AT8xC51SND1 derivatives implement 2304 Bytes of on-chip data RAM. This mem-

ory is divided in two separate areas:

•

256 Bytes of on-chip RAM memory (standard C51 memory).

•

2048 Bytes of on-chip expanded RAM memory (ERAM accessible via MOVX

instructions).

DOC4106 Datasheet(PDF) 14 Page - ATMEL Corporation