Question

Can I use the USB Debug Adapter (UDA) to debug an EFM8 device on my custom PCB as well as to debug the EFM8 device present on the EFM8 Starter Kit (STK) (instead of the on-board J-Link adapter) in Simplicity Studio v4?

Answer

Yes, the Silicon Labs 8-bit USB Debug Adapter (UDA, Figure 1) can be used to debug an EFM8 device in Simplicity Studio v4, regardless of whether it is on a custom board or on a Silicon Labs EFM8 starter kit (i.e. the EFM8 present on the starter kit for evaluation purposes).  Besides the requirement that the device be powered with correct hardware configuration (i.e. bypass capacitors, etc.), the only connections necessary for debugging in this case are C2D, C2CK, and GND.

 

UDA.PNG

 

The following image shows the correct connections to make to debug the EFM8 MCU present on the STK.  Note that if the MCU is powered from the on-board debug USB (J-Link) connector, then the board controller may attempt to drive the target MCU C2 debug signals, creating contention with the USB Debug Adapter C2 signals.  For this reason, it is safest to configure the STK debug to “OFF” mode (or to power the device from the coin cell battery or an external power supply, with the J-link USB connection disconnected).  

 

EFM8STK_C2_header.png

 

The following image shows the correct/corresponding pins needed for use on the UDA:

 

C2D – pin 4

C2CK – pin 7

GND – pins 9, 2, or 3 (only one of these is necessary)

 

UDA_C2_connections.png

Finally, this is what it will look like when SS v4 is connected to the device using the UDA:

 

EFM8_UDA_SSv4_connected.jpg

 

The process to connect to, program, and debug an EFM8 device on a custom board is analogous to the above discussion.  You must simply ensure that the device is powered correctly as recommended for your device and provide a three pin header/connector (connected to C2D, C2CK, and GND) on your custom board similar to that shown on the EFM8 STK, which will serve as an attachment point for the UDA.

 

 

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  • I have a custom pcb using an EFM8BB cpu

    I can load via the USB debug adaptor but unable to set breakpoints/single step or run the firmware via Keil uVision V5

    the USB debug adaptor DLL is SiC8051F.dll id V4.3.0.0

     

    Is there an updte to this?

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  • unable to set breakpoints/single step or run the firmware via Keil uVision V5

    'native Keil or Keil under SS?

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  • Thanks but problem now fixed, I found a post with the following.....

     

    When designing the target board, you should place bypass capacitors (0.1 µF and 4.7 µF) between VDD and ground.  C2CK should have a pull up resistor (no more than 10kOhm, 1kOhm recommended) to VDD.  Do not connect any capacitors to C2CK

     

    THIS FIXED MY PROBLEM...WHY DID SiLABS NOT PUT THIS IN THE REFERENCE MANUAL IT WOULD SAVE PEOPLE A LOT OF WASTED TIME !!!!!!!!

     

    I only needed the 1K

     

    Link

     

    http://community.silabs.com/t5/8-bit-MCU-Knowledge-Base/Debugging-an-8-bit-device-on-an-external-board/ta-p/161604

     

     

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  • Hi ratcatcher,

     

    Thanks for the feedback!  This information should be available in the Debug section in the Typical Connection Diagrams chapter of the data sheet, so please check there for your specific device for this recommendation.  I always recommend checking this section in detail before designing your hardware.

     

    ~Tabi

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  •  WHY DID SiLABS NOT PUT THIS IN THE REFERENCE MANUAL IT WOULD SAVE PEOPLE A LOT OF WASTED TIME

     

    In my opinion the "reference manual" for developing hardware is the devboard schematic

     

    decoupling caps is a mandatory for all chips, SiLabs uCs or not, is basic electronics

     

     

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