AT89SND2CMP3B datasheet(18/242 Pages) ATMEL

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4341H–MP3–10/07

AT8xC51SND2C/MP3B

Program/Code Memory

The AT8xC51SND2C execute up to 64K Bytes of program/code memory. Figure 6-1 shows the

split of internal and external program/code memory spaces depending on the product.

The AT83SND2C product provides the internal program/code memory in ROM memory while

the AT89C51SND2C product provides it in Flash memory. These 2 products do not allow exter-

nal code memory execution.

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

programming. The high voltage needed for programming or erasing Flash cells is generated on-

chip using the standard VDD voltage, made possible by the internal charge pump. Thus, the

AT89C51SND2C can be programmed using only one voltage and allows In-application software

programming. Hardware programming mode is also available using common programming

tools. See the application note ‘Programming T89C51x and AT89C51x with Device

Programmers’.

The AT89C51SND2C implements an additional 4K Bytes of on-chip boot Flash memory pro-

vided in Flash memory. This boot memory is delivered programmed with a standard boot loader

software allowing In-System Programming (ISP). It also contains some Application Program-

ming Interface routines named API routines allowing In Application Programming (IAP) by using

user’s own boot loader.

Figure 6-1.

Program/Code Memory Organization

4K Bytes

Boot Flash

FFFFh

F000h

0000h

64K Bytes

Code Flash

FFFFh

AT89C51SND2C

0000h

64K Bytes

Code ROM

FFFFh

AT83SND2C

F000h

AT89SND2CMP3B Datasheet(PDF) 18 Page - ATMEL Corporation