Interfaces

Debugger interfaces

JTAG

Pull-up / Pull-down Resistors

The lines of a JTAG interface should be pulled up or down according to the table below. The recommended resistor value is 4K7. However, many microcontrollers offering a JTAG interface have internal pull-up/pull-down resistors and as such, don’t require external components on the debugger interface.

TCK Pull-down
TMS Pull-up
TDI Pull-up
TDO Pull-up

References: http://www.latticesemi.com/en/Support/AnswerDatabase/7/9/791

SWD