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JTAG Emulator

Other Parts Discussed in Thread: UCD3138A64

can any one suggest me which JTAG Emulator is usefull for UCD3138A64(ARM7TDMI) Microcontroller and code composer ( V6 ) is the IDE.

  • Hi,

    Both the XDS100v2 and the XDS200 work well with the UCD family of devices. Given the XDS200 will only give you a marginal performance increase (more on this below), I suggest you to invest in the XDS100v2.

    Hope this helps,

    Rafael

    The marginal performance increase happens if you are using the same EVM I used when I did some tests (UCD3138OL40EVM-32). I had to reduce the TCLK speed to about 3MHz to properly operate it with XDS200 (the default speed of 10.368MHz was a no-go). When compared to the XDS100v2 operating at 1MHz by default, this only brings you a marginal performance increase.

    This can have many reasons, ranging from a limitation on the device (not very probable) or a PCB routing (most probable cause). Therefore, if you are designing your own board, the XDS200 may be more interesting as it can give you additional performance.

     

  • desouza said:
    This can have many reasons, ranging from a limitation on the device (not very probable) or a PCB routing (most probable cause). Therefore, if you are designing your own board, the XDS200 may be more interesting as it can give you additional performance.

    I haven't got a UCD3138OL40EVM-32 to try, from a quick look at the documentation:

    a) The UCD3138A64 uses a ARM7TDMI-S processor.

    b) The ARM7TDMI-S Technical Reference Manual (ARM DDI 0234B) Figure 5-4 Clock synchronization shows a "TCK synchronizer" external to the ARM7TDMI-S macrocell to synchronize the JTAG TCK to the internal CLK, and generate a RTCK.

    c) The UCD3138A64 datasheet doesn't show a RTCK at the device pins.

    Therefore, is the issue that the design of the UCD3138A64 hasn't include the ARM recommended "TCK synchronizer", and therefore the JTAG frequency has to run at a slow speed to get reliable JTAG operation?

  • Chester,

    I am not very familiar with this family of devices, but the references seem correct, as well as your conclusion. This made me recall that I have seen the same behaviour happen with ARM9-based devices such as DM355 and DM6446 and fixed-clock JTAG debuggers such as ours. In that case the use of adaptive clock was mandatory (the RTCK pin was featured on those devices).

    I will check with the device designers to see if there is an internal RTCK signal muxed with another pin.

    Thank you and regards,
    Rafael
  • Chester,

    You are correct regarding the absence of the RTCK pin on UCD devices. The final statement is:

    RTCK said:

    Yes, our analysis did conclude that the lack of an RTCK signal from this device's ARM7TDMI-S core does limit the TCK rate to 4 MHz, no matter what emulator is used.

     

    We reported that the XDS560 and XDS560v2 auto-TCK algorithm sets the TCK rate at 4 MHz and that an XDS200 will also operate fine at 4 MHz when overriding the default 10 MHz in the target connection settings.  Not knowing this TCK limitation was the main issue with the XDS200 emulator.  We did much more analysis of the signals and ARM driver, but this is the end result.

    Therefore, my previous recommendation still stands: use the XDS100v2 JTAG debugger, as XDS200 and others will provide only marginal benefit.  

    Thanks for providing grounds for a nice discussion,

    Rafael

  • Hello desouza ,

    Thank you for your information regarding JTAG Emulator, but i have seen in TEXAS INSTRUMENTS Website that they mention ALL ARM PROCESSORS are  supporting XDS100v2 and in  wiki page of XDS100V2  from TEXAS INSTRUMENTS they mention ARM7 PROCESSORS  NOT Supporting XDS100V2,these are the links related to Websites.

     http://processors.wiki.ti.com/index.php/XDS100

     http://www.ti.com/tool/tmdsemu100v2u-14t?keyMatch=xds100v2&tisearch=Search-EN-Everything

    Can you please suggest us which is good to use.

     

    regards,

    Kumaraswamy.

  • Kumaraswamy,

    I am sorry for have missed your last reply. I cleared this confusion on my other reply to you at this link.

    In this case, the recommended model is the XDS200-class of JTAG debuggers.

    I apologize for the confusion,

    Rafael