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  • USB Interface to Microcontroller for Industrial

  • Created: Apr 24, 2015

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The reference design as shown is a RAppID boot loader tool connected to a TWR-PXR40 board. RAppID boot loader is a very useful tool in loading a new firmware to a microcontroller, and doing updates in its firmware without having access to the microcontroller's program or debug pins. It also contains a special module, which is called boot assist module (BAM) that can be used in order to download code to the microcontroller after it comes out of the factory.

The design made use of the USBSER IC as an USB-to-serial bidirectional bridge that allows in connecting to the TWR-IND-IO board and to the RAppID boot loader using a USB port with only a few external components involved. The USBSER IC is connected to a USB port in the board, where signal is transmitted from to the USB and UART ports respectively. LED diodes are placed in the circuit as an indicator in order to identify the function of the circuit. The capacitors help in stabilizing component while in operation. The resistor acts as limiter for possible surges and voltage reference for supplies.

The BAM module of the PXR40 microcontroller together with the RAppID boot loader tool is a very good option for application factory programming because it provides an easy way to download code using a serial interface instead of a full JTAG interface. Thus, this will open new possibilities in accessing more designs and functions.



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