topic Re: watchdog on LPC11A04UK in LPC Microcontrollers

watchdog on LPC11A04UK

lpcware — Wed, 15 Jun 2016 19:38:14 GMT

Content originally posted in LPCWare by piter on Tue Nov 27 06:37:34 MST 2012
Hi,

I'm programming and debugging the LPC11A04 by SWD, and all works well.

Except when I activate the watchdog, the chip is inaccessible and isn't responding to reprogramming / erase functions.

Has anyone seen this behavior before (and know what to do about it)?

Used tools: MDK-ARM with ULINK2.

Re: watchdog on LPC11A04UK

lpcware — Wed, 15 Jun 2016 19:38:15 GMT

Content originally posted in LPCWare by Daniel Widyanto on Mon Dec 10 21:17:29 MST 2012
Hi,

Once you enable the watchdog, you won't be able to turn it off. The problem is that when you are doing Flash programming using SWD, there are probability that your code to activate the watchdog already run, before the SWD is able to stop the MCU. Therefore, the MCU will be reset during Flash programming / erase (due to the watchdog).

To solve it, force the MCU to enter ISP mode first (ie. pull PIO0_1 LOW while RESET), before using the SWD to do the Flash programming.

Re: watchdog on LPC11A04UK

lpcware — Wed, 15 Jun 2016 19:38:15 GMT

Content originally posted in LPCWare by piter on Tue Dec 11 03:28:28 MST 2012
Hi Daniel,

YES! This works fine. Thanks a lot.

Re: watchdog on LPC11A04UK

lpcware — Wed, 15 Jun 2016 19:38:16 GMT

Content originally posted in LPCWare by you_sun on Thu Jan 10 00:18:02 MST 2013
Hi Piter,

I am to LPC11A04, but I have a project will use this chip, which develop board are you using? I want evaluate the chip before I start design a board. could you please give me some suggestion, thank you very much.

Re: watchdog on LPC11A04UK

lpcware — Wed, 15 Jun 2016 19:38:16 GMT

Content originally posted in LPCWare by piter on Sat Jan 19 06:01:49 MST 2013
Hi you_sun,

I didn't use a specific developmentboard.
I've started my project by using a board with a LPC11C24. Most blocks I've used are equal in the LPC11C24 / LPC11A04.
Make sure that you have access to P0.1, in case you're planning to use the watchdog ;)

br.
Piter