T83C51SND1-ROTIL datasheet(15/60 Pages) ATMEL

15 / 60 page

T8xC51SND1

Rev. D – 15-Nov-01

7. Address Spaces

The T8xC51SND1 derivatives implement four different address spaces:

•

Program/Code Memory

•

Boot Memory

•

Data Memory

•

Special Function Registers (SFRs)

7.1 Code Memory

The T89C51SND1 and T83C51SND1 implement 64 Kbytes of on-chip program/code

memory. The T83C51SND1 product provides the internal program/code memory in

ROM technology while the T89C51SND1 product provides it in FLASH technology.

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

erasure and programming. Thanks to the internal charge pump, the high voltage needed

for programming or erasing FLASH cells is generated on-chip using the standard VDD

voltage. Thus, the T89C51SND1 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 tool.

7.2 Boot Memory

The T89C51SND1 implements 4 Kbytes of on-chip boot memory provided in FLASH

technology. This boot memory is delivered programmed with a standard boot loader

software allowing in system programming commonly known as ISP. It also contains

some Application Programming Interfaces routines commonly known as API allowing

user to develop its own boot loader.

7.3 Data Memory

The T89C51CC01 derivatives implement 2304 bytes of on-chip data RAM. This memory

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).

7.4 Special Function Registers

The Special Function Registers (SFRs) of the T89C51CC01 derivatives fall into the cat-

egories detailed in Table 16 to Table 32. The relative addresses of these SFRs are

provided together with their reset values in Table 33. In this table, the bit-addressable

registers are identified by Note 1.

T83C51SND1-ROTIL Datasheet(PDF) 15 Page - ATMEL Corporation