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AFE8000: JTAG Interface

Part Number: AFE8000

Tool/software:

Hi,

I have several questions regarding the JTAG interface of the AFE8000 component:

  1.) On the datasheet, TMS is mapped to G9 and TRST to R7:

On the EVB, TMS is connected to R7 and TRST to G9.

  - Why there is a change in the pins?

  - Which connection is the correct one?

  2.) What is the maximum operation frequency for JTAG?

  3.) Are there any required pull-up/down resistors?

  4.) Do you have a recommendation for JTAG Debugger for this component?

Best regards,

Avihay.

  • Hi Avihay,

    Firstly, I want to point out that only functionality available for users through JTAG is boundary scan. Other JTAG modes are for TI internal use only. AFE79xx_JTAG_Boundary_Scan.zip file on the secure folder has instructions for boundary scan. Most users don't use JTAG and leave these pins unconnected. Note that BIST0 and BIST1 pins need to be controlled to set AFE to normal operation or Boundary Scan mode (instructions are part of "AFE79xx_JTAG_Boundary_Scan.zip" file)

    SPI is used for any debug on user systems. 

    1. Pin mapping given in the Datasheet is correct. TMS is mapped to G9 and TRST is mapped to R7. I apologize for the confusion due to mapping mentioned in the EVM. please follow the datasheet pin mapping. 

    2. JTAG boundary scan can be operated at 7.5MHz maximum rate.

    3. If you plan on using JTAG for boundary scan, you can have a 10k pull down on TRST to avoid any unwanted glitchy resets. Otherwise, you can leave these pins unconnected. 

    4. For boundary scan at TI, JTAG from tester (ATE) is used. As this is only for boundary scan, we don't have any debugger recommendations. 

    Regards,

    Vijay