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TMS320F28379D: JTAG and Oscillator

rajesh beesetty
Expert 1355 points

Part Number: TMS320F28379D

Hello TI,

I would like to know whether the connections I did for JTAG and Oscillator are correct. Anyways the CAP 86, 87 values are not mentioned but I ensure I will place the values recommended on F28379D Launchpad.

The schematic is attached

  • 0
    TI__Mastermind 42195 points

    Rajesh,

    it looks like you are trying to use the TI14 pin standard. From what I can tell it looks OK. FYI here is a good reference: http://software-dl.ti.com/ccs/esd/documents/xdsdebugprobes/emu_jtag_connectors.html 

    In addition to the above you will need to follow the guidelines in  5.9.5 "Emulation/JTAG" of the Datasheet, which looks OK to me. https://www.ti.com/lit/gpn/tms320f28379d 

    We specify C1 and C2 for the oscillator circuit. These must be equal and between specific values, to determine these values please see Table 5-15. "Crystal Oscillator Parameters" of the Datasheet. https://www.ti.com/lit/gpn/tms320f28379d 

    You must also match the spec that the crystal manufacture specifies. The manufacturer typically specifies CL, which is the total capacitance seen by the XTAL. you will need to look this up and then choose a crystal that has a CL which enables you to choose a C1 and C2 value which fall within our spec as well. 

    Remember  the fundamental formula here is CL = (C1 * C2) / (C1 + C2) + Cstray. Cstray is the PCB's incidental capacitance.

    Regards,
    Cody