stlink can not work normally: The Reset signal keep low when i push download button of iar.

[100asong]

Posted on December 27, 2011 at 14:29

hi,

    stlink jtag can not work normally.The Reset signal keep low when i push download button of iar.

[Tesla DeLorean]

Posted on December 27, 2011 at 14:45

NRST is ZERO, processor NO function

How is the Reset on your board achieved? Nominally you want it driven open-collector/drain with a pull up. If your circuit drives the signal low, or you use push-pull drivers the chip will not reset properly. Typically external JTAG pods cannot get the pin HIGH if other sources are driving it LOW.