AT89C51AC3-RDTIM datasheet(56/140 Pages) ATMEL

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AT89C51AC3

4383D–8051–02/08

In-System

Programming (ISP)

With the implementation of the User Space (FM0) and the Boot Space (FM1) in Flash

technology the AT89C51AC3 allows the system engineer the development of applica-

tions with a very high level of flexibility. This flexibility is based on the possibility to alter

the customer program at any stages of a product’s life:

•

Before assembly the 1st personalization of the product by programming in the FM0

and if needed also a customized Boot loader in the FM1.

Atmel provide also a standard UART Boot loader by default.

•

After assembling on the PCB in its final embedded position by serial mode via the

UART.

This In-System Programming (ISP) allows code modification over the total lifetime of the

product.

Besides the default Boot loader Atmel provide to the customer also all the needed Appli-

cation-Programming-Interfaces (API) which are needed for the ISP. The API are located

also in the Boot memory.

This allow the customer to have a full use of the 64-Kbyte user memory.

Flash Programming and

Erasure

There are three methods of programming the Flash memory:

•

The Atmel bootloader located in FM1 is activated by the application. Low level API

routines (located in FM1)will be used to program FM0. The interface used for serial

downloading to FM0 is the UART. API can be called also by the user’s bootloader

located in FM0 at [SBV]00h.

•

A further method exists in activating the Atmel boot loader by hardware activation.

•

The FM0 can be programmed also by the parallel mode using a programmer.

Figure 29. Flash Memory Mapping

Boot Process

Software Boot Process

Example

Many algorithms can be used for the software boot process. Before describing them,

The description of the different flags and Bytes is given below:

F800h

FFFFh

64K Bytes

Flash memory

2K Bytes IAP

bootloader

FM0

FM1

Custom

Boot Loader

[SBV]00h

FFFFh

FM1 mapped between F800h and FFFFh

when API called

0000h

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