Flash Magic Forum

In-System Programming Support => P89V51Rx2/P89LV51Rx2 => Topic started by: twtryzhy on January 13, 2010, 07:22:03 pm

Title: ISP broken down
Post by: twtryzhy on January 13, 2010, 07:22:03 pm
Hi,every one!

    I have been useing P89LV51RD2 for a long time.But recently i met a difficult, which is the ISP broken down suddenly after i modified my program to add another function to it.The promotion information is can't communiction ,ask me change the baud rate, i acted follow it ,but it didn't work.And then , i chaged a new chip , the question go back once more.

   I met the same question a month ago, after i download a new vision of FlashMgic, i resolved it .Now, it came back again, what i coud do?

    Before post this topic , i read the Andy Ayre's "Read First Before Posting ",but not work,I guess maybe the bootloader broken down,but ,why did it down? because of my program?If yes, what program would act like this?
Title: Re: ISP broken down
Post by: Andy Ayre on January 14, 2010, 12:33:03 pm
You need to send a stream of 'U's to the device using a terminal program and while doing that reset it. If you don't get a 'U' back then the bootloader is not starting for some reason and therefore Flash Magic won't work with it.

Use 8 bits, no parity, 1 stop bit, no flow control and a reasonable baudrate for your crystal frequency. For example 9600 baud at 10MHz or higher.

Andy
Title: Re: ISP broken down
Post by: twtryzhy on January 14, 2010, 07:23:25 pm
Thanks! I'll have a try!
Title: Re: ISP broken down
Post by: twtryzhy on January 14, 2010, 11:44:24 pm
Hi,Andy,
    I have do all on a good chip and a 'bad' chip follow your advision. But after I sent a stream of 'U',I get nothing at all ! What happened?
    Btw,are you sure the sent 'U' is HEX format?

    Another question: If  I find out that the reason is the bootloader doesnt work? What can I do next?
It seems it's my code make the bootloader break down, but the user memory and the bootloader memory is indepened in memory space, how does it do that?
Title: Re: ISP broken down
Post by: Andy Ayre on January 15, 2010, 07:24:21 am
If your code uses IAP then it might have been possible to erase block 1, where the bootloader is located. I think the only way to learn more would be to put the devices into a parallel programmer and see if block 1 has been erased. If you use IAP or jump to the IAP address (see the NXP user manual) then remove that code and test on a new device, perhaps.

Andy
Title: Re: ISP broken down
Post by: twtryzhy on January 16, 2010, 04:56:49 am
Did my code uses IAP? I nearly could be sure it's impossible, because the code is combined by two Independent codes, and the two codes has been downloaded into the chip and work well independantly. The only thing I did just to combine the two code into one.
Anyway,Thank you ,Andy!