Messages

Andy,

Are you sure you are not confusing /PSEN (output, to be connected to code memory output enable pin), with /EA (input, determining whether external or internal code memory is to be used)?

/PSEN should be left floating.

Jan Waclawek

As this is a non-ISP non-FlashMagic question, you better come to 8052.com Forum with this question.

Jan Waclawek

I am working on p89v51rb2fn philips microcontroller , I programmed it and
tested it , the second time I earsed the chip and downloaded the same program

How did you "erase the chip"? Does "downloaded the same program" mean successful programming?

it didn't work !! what could couse some thing like that ?

What does exactly mean "it didn't work"? What is it supposed to do and how does it fail to do so?

JW

I don't quite understand what's your problem with FLIP, but anyway, as this is a FlashMagic-specific forum, you better should repost your question on the 8052.com's Forum (please observe the rules for posting there).

JW

It is vital always to use the full marking of the part, including the prefix (OK you might omit the suffixes denoting the package/temperature grade).
There is no Philips/NXP made chip with RE2 suffix; and FlashMagic is a NXP-sponsored project, aimed at programming NXP-chips. You are most probably talking about Atmel's AT89C51RE2, for which the proper programming tool is FLIP, to be found at Atmel's webpages.

JW

I interpreted the poster's message as meaning that they were able to execute their code, but not get back into ISP mode. Flash Magic automatically clears the status byte after programming, so if you want to reset back into the bootloader you need to explicitly set the status byte again.

This is what they appear to do, indeed, i.e. enter the bootloader from the user code via programming the statys byte.

It appears then, that after having entered the bootloader and programmed the part successfully using FM, they used an option in FM to automatically run the user code. I don't have/use '668, but the datasheet does not mention a "reset" option via ISP (such as that in the 'V51RD2's ISP command set) - isn't this some sort of misunderstanding?

Jan Waclawek

To get the device back into ISP mode you must meet the requirements for ISP entry as described in the device user manual. Have you confirmed you are doing that with a scope? What did you find?

But, Andy, setting the statusbyte to nonzero overrides the hardware bootloader entry condition - and there is nothing to check with scope on that.

Nevertheless, from the OP's post it's not clear for me, how does he reset the device after programming the statusbyte, nor what are exactly the symptoms...

Jan Waclawek

It does not matter what do you attempt to program into the mcu, as the bootloader won't start.

You might first want to verify that the serial path is OK. Read e.g. http://www.8052.com/forum/thread.phtml?thread=151229 and the links given there.

If the serial path is OK and still problems programming, you might want to make a screenshot (Alt+PrintScreen, then paste into a suitable graphics program, e.g. IrfanView) of your setup of FlashMagic and post it here.

JW

[C]

==> The trick is to send a 'U' character almost immediately after coming out of RESET.

As I said above: This refers to "manual" programming, e.g. from a general-purpose terminal emulator. You don't need to be bothered by this when using FLashMagic - FM sdends out a stream of Us when the "reset now" window appears, so if you reset the mcu at that moment, it will catch on one of the Us.

The reason why U shall be sent immediately after reset lies in the method how 'V51RD2's bootloader is entered. It is not entered upon pulling down a pin like the older P89C51RD2. Rather, after hardware reset, the P89V51RD2 waits for an 'U' to arrive, but it times out after a fraction of second and then starts the user application (performing a so called software reset).

Refer to the P89V51RD2's datasheet for further details.

JW

what is the purpose of doing it..??
and what will heppen if i am doing it or not..??

Doing what?

==> The trick is to send a 'U' character almost immediately after coming out of RESET.


can you please clarify it in detail...Huh

This refers to "manual" programming, e.g. from a general-purpose terminal emulator. You don't need to be bothered by this when using FM.

JW

It should disappear immediately after you have released the reset button.

For further help, read
http://forum.flashmagictool.com/index.php?topic=3232.0
http://forum.flashmagictool.com/index.php?topic=3273.0

JW

[C]

Yes. Just hold down the RESET pushbutton, press START in FlashMagic (provided that you have selected the appropriate chip - caution, don't select the P89C51Rx2!!! -  a moderate baudrate (say 9600 for beginning, later you can increase it), selected the hexfile to upload etc. etc.), and when the "Reset now" window appears, release the RESET button.

JW

None needed. Just use a normal RS232 transceiver such as MAX232 between the RxD and TxD pins of the mcu and PC.

There is an optional reset circuit connected to DTR - see the manual (pdf) which comes with FlashMagic - but this is not necessary.

JW

No, but it's not necessary to modify the hex file so is a bit easier than using a parallel programmer.

Oh I see, thanks Andy.

Nevertheless it seems that some users do prefer parallel programming of the bootloader update, and possibly with the "bootloader entry on pin" option switched already on - I know it's beyond FlashMagic, it's just the defunct (or barely functional) NXP web and forum why these question gets asked here - there was an another separate thread about this topic recently.

Jan Waclawek

Note that the bootloader updater is designed to work with the corresponding feature in Flash Magic. Choose Update Bootloader from the ISP menu

Hummmm... Does this meant that there is any sort of magic performed by FlashMagic, other than "burn" the updater as it would any other application, then run it and re-autobaud?

Jan Waclawek