Loginway

Microchip published new application note AN1094 “Bootloader for dsPIC30F/33F and PIC24F/24H Devices”.

The bootloader for dsPIC30F/33F and PIC24H/24F devices is used to load and run an application on the target device. The bootloader consists of two applications:

• Target side bootloader application which must be programmed into dsPIC30F/33F or PIC24F/24H program memory prior to bootloader operation.

• Host PC bootloader application which communicates with the target side bootloader.

The bootloader parses the program HEX file and then copies it into the appropriate program and EEPROM memory (if present) on the target device via the communication channel (UART, CAN, etc.). The bootloader target application is located in the dedicated program memory region, starting at address 0×100 (for dsPIC30F devices) or 0×400 (for all other device families). On start-up, the bootloader reads program memory address 0×600 (for dsPIC30F family) or address 0xC00 (for all other device families), which contains a bootloader delay value. If the bootloader fails to detect UART activity within the time period specified by the delay value, it suspends itself and transfers execution to the user application located at program memory address 0×602 (for dsPIC30F family) or address 0xC02 (for all other families). On the other hand, if the bootloader detects UART activity before it suspends itself, it programs both EEPROM (if present) and program memories with the data it receives from the bootloader host application via UART interface. The bootloader host application parses the HEX file containing the user application (generated by MPLAB® IDE and sends this data to the bootloader target application via UART. The bootloader host application also supports additional features, such as read of program and EEPROM memories.

More datails at AN1094 Application Note.