AN247 View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

AN247

A CAN Bootloader for PIC18F CAN Microcontrollers

Microchip Technology 

AN247

RESOURCES

For most builds, the PIC18F CAN bootloader resides

within the device’s Boot Block (000h to 1FFh), and

does not impact the normal Program Memory space

beyond the relocation of the interrupt vectors.

As noted, some combinations of compile time options

(for example, selecting both PG mode and self-verify)

will result in a bootloader that exceeds the Boot Block

size. In these cases, it will be necessary to relocate any

user application code and the interrupt vectors above

the boundary of the bootloader, being careful to avoid

code overlap. If Program Memory space is not critical,

the optimal solution may be to locate all application

code and the interrupt vectors above the upper bound-

ary of Block 0 (1FFFh). Write protecting Block 0 to

protect the bootloader is desirable, but not essential.

The bootloader uses 12 bytes of data SRAM during

operation. It also uses 1 byte of data EEPROM at all

times, as the normal operation/bootloader flag.

REFERENCES

W. Lawrenz, CAN System Engineering From Theory to

Practical Applications. New York: Springer-Verlag

New York Inc., 1997.

MPLAB-CXX Compiler User’s Guide, Microchip

Technology Inc., 2000 (Document number DS51217).

Microchip Technology Inc., Application Note AN851, “A

FLASH Bootloader for PIC16 and PIC18 Devices”

(Document number DS00851).

DS00247A-page 10

 2003 Microchip Technology Inc.

Share Link: