at89c51ac3-s3sim ATMEL Corporation, at89c51ac3-s3sim Datasheet - Page 56

• Manufacturer Part Number: at89c51ac3-s3sim
• Description: At89c51ac3 Enhanced 8-bit Microcontroller With 64kb Flash Memory
• Manufacturer: ATMEL Corporation

In-System
Programming (ISP)
Flash Programming and
Erasure
Boot Process
Software Boot Process
Example
56
AT89C51AC3
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:
•
•
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.
There are three methods of programming the Flash memory:
•
•
•
Figure 29. Flash Memory Mapping
Many algorithms can be used for the software boot process. Before describing them,
The description of the different flags and Bytes is given below:
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.
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.
[SBV]00h
FFFFh
0000h
Flash memory
64K Bytes
Custom
Boot Loader
FM0
F800h
FM1 mapped between F800h and FFFFh
when API called
2K Bytes IAP
bootloader
FM1
FFFFh
4383D–8051–02/08