User Manual

T89C51AC2

Rev. B – 19-Dec-01

10. In-System-

Programming (ISP)

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

technology the T89C51A C2 allows the system engineer the development of applications

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

customer program at any stage s of a product’s life:

• Be fore assem bly the 1st personalization of the produc t by programm ing in the FM0

and if needed also a customized B oot loader in t he FM1.

Atmel provide also a standard Boot loader by default UART.

• After as se mbl ing on the PCB i n i ts final embedded position by serial mode via the

UART.

This In-System-Programming (ISP) allows code modi fica tion over the total lifetime of the

produc t.

Besides the def ault B oot loader Atmel provide to the customer also all the needed App li-

cation-Programming-Interfaces (API) which are needed for the ISP. The AP I are locat ed

also in the Boot m emory.

This allow the cus tomer t o have a full use of the 32 Kbyt e user memory.

10.1 Flash Program ming

and Erasure

There are three methods of program ming the Flash m emory:

• The Atmel bootloader located in FM1 is ac tivated by the application. Low level API

routines (located in FM1)will be used to program F M0. The interf ac e used for seria l

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

located in FM0 at [SBV]00h.

• A further m etho d exist in activating the Atmel boot loader by hardwa re ac t ivation.

• The FM0 can be programmed also by the parallel m ode using a programmer.

Figure 16. F lash Memory Map ping

F800h

7FFF h

32 Kbytes

Flash memory

2KbytesIAP

bootloader

FM0

FM1

Custom

Boot Loader

[SBV]00h

FFFFh

FM1 mapped between F800h and F FFFh

w hen API called

0000h