The frequency is low when NRF51822 connected JLink via SWD

[aileen]

If I want to connect the NRF51822 board to Keil using JLink via SWD, I found the SW's clock frequency must below 20kHz. If I choose the higher frequency, the Keil can not scan the chip. Any suggestion?

P.S. The SWDIO is connected directly, and SWCLK is pulled down via a 12k resistor. And the reset module is just using one 4.7k resistor and one 0.1uf capacity.

Thanks very much!

[MartinBL]

Hi.

• Is this a custom board or a development kit?
• What nRF51 revision are you using? Refer to the compatibility matrix.
• What sort of debugger do you use?
• If it is a custom board can you please edit your question and include a schematic and preferably your PCB layout? You can create a support ticket on our support portal, MyPage, if you want confidentiality.