AT89C5115
In-System
Programming (ISP)
With the implementation of the User Space (FM0) and the Boot Space (FM1) in Flash
technology the T89C5115 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 mounting the chip on the PCB, FM0 flash can be programmed with the
application code. FM1 is always preprogrammed by Atmel with a bootloader (UART
bootloader).(1)
•
Once the chip is mounted on the PCB, it can be programmed by serial mode via the
UART.
Note:
1. The user can also program his own bootloader in FM1.
This ISP allows code modification over the total lifetime of the product.
Besides the default Bootloaders Atmel provide customers all the needed Application-
Programming-Interfaces (API) which are needed for the ISP. The API are located in the
Boot memory.
This allow the customer to have a full use of the 16-Kbyte user memory.
Flash Programming and There are three methods for programming the Flash memory:
Erasure
•
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.
See the Section “Hardware Security Byte”.
The FM0 can be programmed also by the parallel mode using a programmer.
Figure 18. Flash Memory Mapping
FFFFh
2K Bytes IAP
Bootloader
FM1
F800h
3FFFh
FM1 Mapped between F800h and FFFFh
when API Called
Custom
Bootloader
[SBV]00h
16K Bytes
Flash Memory
FM0
0000h
45
4128F–8051–05/06
ATMEL [ ATMEL ]
