topic Re: OM13094 SWD to program the LPC54605J512 in LPC Microcontrollers

OM13094 SWD to program the LPC54605J512

terence_kong — Tue, 19 Nov 2019 23:41:30 GMT

Hi NXP,

We are using the OM13094 to program our target board and recently damage couple chips already. And always on the RST pin.

On the damaged target boards, the MCU RST pin always held low and the RST resistance to ground less than 10 ohms...So we have confirmed the RST pin is damaged after programming by the OM13094 eva board.

On the OM3094 board, the following jumpers has been set :

- JP2 2-3 connected

- JP1 shorted

- Use P1, SWD to program our target board

Our board is running at 1.8V

- Use SWD to program the LPC54605

Question:

1) Does the OM13094 eva board support 1.8V off board programming?

2) How to avoid the RST pin damage?

Re: OM13094 SWD to program the LPC54605J512

xiangjun_rong — Thu, 21 Nov 2019 05:59:09 GMT

Hi, Terence,

Regarding your issue that "We are using the OM13094 to program our target board and recently damage couple chips already. And always on the RST pin.", I think I can only give you suggestion.

You said that you use 1.8V logic, do you mean that the VDD of the target processor LPC54605 is 1.8V? because you short the PIN2&3 of JP2, which means that the ResetN, SWDIO and SWDCLK pins of LPC54605 are all 1.8V logic, so I think there is no problem, because all VDD and ResetN, SWDIO and SWDCLK pins signal voltage of LPC54605 are all 1.8V.

I suppose that if VDD is 3.3V, but you input 1.8V logic voltage for signal pin for example Reset pin, maybe there is problem, because the 1.8V voltage is a middle voltage.

We use 3.3V logic to download code and debug, never have problem. If possible, can you use 3.3V for both VDD and SWD signals for LPC54605?

Xiangjun rong

Re: OM13094 SWD to program the LPC54605J512

terence_kong — Thu, 21 Nov 2019 15:07:08 GMT

Hi Rong,

VDD, RST and SWDIO/CLK are running at 1.8V on our target board.

Wondering what is causing the RST pin damage..?

Re: OM13094 SWD to program the LPC54605J512

xiangjun_rong — Fri, 22 Nov 2019 02:09:17 GMT

Hi, Terence,

Have you tested the IF_RST pin voltage? is it 1.8V or 3.3V?

XiangJun Rong

Re: OM13094 SWD to program the LPC54605J512

terence_kong — Fri, 22 Nov 2019 04:13:45 GMT

Yes it is 1.8V

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Re: OM13094 SWD to program the LPC54605J512

xiangjun_rong — Tue, 26 Nov 2019 03:06:53 GMT

Hi, Terence,

Frankly speaking, I have not idea why the chip can be damaged with 1.8V logic. If you use 3.3V logic, do you have any issue?

Xiangjun Rong