ATmega169P datasheet(284/393 Pages) ATMEL

Part #	ATmega169P

Description	8-bit Microcontroller with 16K Bytes In-System Programmable Flash

PDF	393 Pages

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Manufacturer	ATMEL [ATMEL Corporation]

Direct Link	http://www.atmel.com

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284 / 393 page

284

8018N–AVR–08/09

ATmega169P

26.6

Entering the Boot Loader Program

Entering the Boot Loader takes place by a jump or call from the application program. This may

be initiated by a trigger such as a command received via USART, or SPI interface. Alternatively,

the Boot Reset Fuse can be programmed so that the Reset Vector is pointing to the Boot Flash

start address after a reset. In this case, the Boot Loader is started after a reset. After the applica-

tion code is loaded, the program can start executing the application code. Note that the fuses

cannot be changed by the MCU itself. This means that once the Boot Reset Fuse is pro-

grammed, the Reset Vector will always point to the Boot Loader Reset and the fuse can only be

changed through the serial or parallel programming interface.

Note:

1. “1” means unprogrammed, “0” means programmed

Table 26-4.

Boot Reset Fuse(1)

BOOTRST

Reset Address

Reset Vector = Application Reset (address 0x0000)

Reset Vector = Boot Loader Reset (see Table 26-6 on page 291)

ATmega169P Datasheet(PDF) 284 Page - ATMEL Corporation