Rainbow Electronics T89C51AC2 - Manual (Page 40)

40
T89C51AC2
Rev. B – 19-Dec-01
10. In-System-
Programming (ISP)
With the implementation of the User Space (FM0) and the Boot Space (FM1) in Flash
technology the T89C51AC2 allows the system engineer the development of applications
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 Boot loader by default UART.
• 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 32 Kbyte user memory.
10.1 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 user’s bootloader
located in FM0 at [SBV]00h.
• A further method exist in activating the Atmel boot loader by hardware activation.
• The FM0 can be programmed also by the parallel mode using a programmer.
Figure 16. Flash Memory Mapping
F800h
7FFFh
32 Kbytes
Flash memory
2 Kbytes IAP
bootloader
FM0
FM1
Custom
Boot Loader
[SBV]00h
FFFFh
FM1 mapped between F800h and FFFFh
when API called
0000h