About pullup / pulldown resitor in JTAG

Discussion in 'General Electronics Chat' started by beyondtu, Oct 6, 2010.

  1. beyondtu

    Thread Starter New Member

    Oct 6, 2010
    Hi All,
    I offten heard some feedback from our JTAG tester vendor that the JTAG can not work because the pull-up resistor on TCK pin is too small (28OHM, 47OHM...), I do not know why this resistor will affect test, some of them told me it caused that we need high speed, some of them told me it need more current, so can anyone help me?
    BTW, I want to know how to select pull-up and pull-down resistor and the value in circuit.