USB PIC Bootloader is a resident bootloader for PIC18 series of Enhanced Flash USB Microcontrollers. It allows you to program a new firmware application image into the chip using the standard USB connectivity of your device.
- USB PIC Bootloader fully complies with USB Specification for Human Input Devices (HID) and all interfacing is done via standard HID driver from Microsoft.
- XTEA encryption algorithm is used to protect privacy of firmware application updated with USB PIC Bootloader.
- USB PIC Bootloader code is write-protected and cannot be overwritten by firmware.
- Firmware update or user mode is selected by SW and/or HW switch.
USB PIC Bootloader is a small program that stays in the first 2,048 bytes of the program memory of the Microchip PIC Microcontroller. Bootloader runs at the boot time (when the processor has just been reset) and is capable of loading a complete application program into a processor's memory. With the USB PIC Bootloader loaded, there are two distinct modes of operation: firmware update mode and user mode. USB PIC Bootloader uses the EEPROM mark and/or hardware switch to determine which mode to run in.
Firmware Update Mode
In firmware update mode USB PIC Bootloader utilizes USB connection of Microchip PIC Microcontroller to communicate with PC and load the new application code. Once the programming is done, the USB PIC Bootloader switches to user mode, the processor is reset and begins running the newly loaded code.
In user mode USB PIC Bootloader simply remap reset and interrupt vectors to user mode firmware application.