Author Topic: LPC1xxx Help Needed  (Read 5931 times)


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LPC1xxx Help Needed
« on: December 14, 2011, 11:55:36 am »
Hi Andy,

I do need your help.

I use Flash magic program the unit with LPC1102 MCU.
If the LPC1102 is empty, I am able to program it using Flashmagic without issue.
If the LPC1102 was programmed and I want to erase/reprogram it using Flashmagic, but failed to autobaud.

Here is what I did.
1. In my FW, very early stage inside the main routine, I revoke the ISP by detecting one GPIO pin at low level.
This code is exactly for the apps note from NXP.
2. Hardware I am using FDTI USB to RS232 baord and just use TXD, RXD and VCC/GND.
3. I want read security signature in Flashmagic, it always says"failed to autobaud....".
4. When I use terminal, only right after reset, when I enter "?", I can get "synchronized" from the output screen. Any other time, no matter what I type, nothing show up in the output screen.
5. Is the auto baud feature enabled by default in LPC1102? Do my FW need enable this feature before revoke ISP mode?
6. I browsed all the related-info on the website by you and other persons and still cannot figure it out.

Can you help out?
Thanks a lot!

Andy Ayre

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Re: LPC1xxx Help Needed
« Reply #1 on: December 15, 2011, 01:51:19 am »
Please start a new topic for new questions. I've fixed it for you this time.

I am not familiar with the application note you mention - an application note number would have been helpful...

My guess is that something is going wrong when the bootloader is invoked from your application. Perhaps the stack is not being correct set up? If you pull pin PIO0_1 low at reset does it work then?

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Re: LPC1xxx Help Needed
« Reply #2 on: March 07, 2012, 05:49:43 pm »

It is a code issue. The ISP revoke code works solid.

LPC1102 is very tiny and nice MCU.