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FLIP wouldn't help either, as the AT89S52 is SPI-ISP programmable and FLIP (as well as FlashMagic) is for UART-ISP programming (such as for AT89C51RD2/ED2 etc.). There are a couple of programs for the SPI-ISP intended to work over serial cables, but they mostly would fail over USB-to-serial cables, too, as these cables are not intended to work for the bint-banging which is how the SPI interface is simulated.

Btw. with USB-to-parallel cables, the problem is not Prolific-specific, but the same as described above: these cables simply can't work for the bit-banged interfaces as they support only printing on LPT and nothing else.

Jan Waclawek

Id' guess this is the classical problem of RC reset...

Jan Waclawek

It is much more important to look at the chip inside than the "brand" of the cable. Certain prolific-chip based cables are known bad - see http://www.8052.com/forum/thread.phtml?thread=97853. Unfortunately, the cheap "cables" tend to be based exactly on this chip. It is also important to get the latest drivers, the drivers provided on the accompanying CD are often out of date and buggy - the best resource is again the chipmakers' web, rather than the "manufacturer"'s.

Jan Waclawek

Dear H S Thakur,

If it's not you or your colleague asking there - there is a discussion on the very same topic running currently on 8052.com's forum: http://www.8052.com/forum/thread.phtml?thread=126180

Jan Waclawek

> PSEN pin connect with 3V

Wrong, leave it floating.

> EA connect with Ground

Wrong, tie it to VDD

> RESET : Using power on Reset circuit ,but use 10K Ohm instead of 8.2K

Might work, but I'd recommend a proper reset IC

Jan Waclawek

CodeGuy wrote:

> Sorry, I do not sure that which forum I should go to raise my
> IAP question. Came to this forum, hopefully could find helps
> from the experts like you.

I'd recommend to move to 8052.com's Forum.

It would be nice to discuss it on Philips' (or, now rather NXP's) Forum, but that is ... ehm ... not too well functional...

> Joe, do your mind telling me that what is the access time to
> write a byte to flash rom using IAP? I could get this
> information from datasheet.

The Philips datasheet leaves a LOT of questions behind... I often use the apparently equivalent SST part datasheet which says 30ms for sector-erase and 50us for byte programming; plus the IAP software overhead (but it also says something on inverse proportionality on programming clock, with no further indication how does this apply to IAP) - however, there is no guarantee for this figures, Philips might have have manufactured different batches of the parts at different vendors... The definitive answer shall come from Philips (NXP).

A nice way would be to have a copy of your interrupt service routines in Block1, running properly during the programming. Again, the documentation provided by Philips (more precisely, the lack of it) prevents to do this properly.

Jan Waclawek

The bootloader is "the thing" which enables you to download anything via ISP, so of it is "blocked", there is no way how to download anything via ISP and you need to resort to parallel programming (in a device programmer).

However, there might be a chance that you have switched on the "softICE mode" accidentally, which might happen if you choose by mistake P89C51RD2 instead of P89V51RD2 in FlashMagic. Search for "unsoftice".

Jan Waclawek

Some hints for using Linux for '51 development can be found in http://www.8052.com/users/redtommo/
There are also several other members of the 8052.com forum who appear to be active Linux users, so if in troubles you could ask perhaps there.

Jan Waclawek

OK, but have you seen ANY documentation on an IC with this name?
Any links?

JW



Post Edited (07-25-06 00:33)

Andy,

Are you ABSOLUTELY SURE there is no bootvector on this device?
I can't find anything on P89V51FBC  on the Philips website, and when I tried googling for it, it returned only one result, hinting, that this is identical to P89C51RD2Hxx...?

Jan Waclawek

Actually, this should perhaps be considered as a bug in the bootloader code (rather than FM's bug). The bootloader should check the status of clock bit before it attempts to program it + change the baudrate.

Of course, it is easier to persuade Andy to fix it in FM than Philips to fix it in the bootloader... :-)

Jan Waclawek

The bootloader is not lost (AFAIK it is in ROM); most probably this is the typical case of infamous "bootvector loss".

During bulkerase, both the data flash and the bootvector gets erased, but that process takes some time. Normally, after bulkerase, the internal bootloader restores the default bootvector (and status byte) automatically after the bulkerase finished. But, if during the bulkerase is in progress, the watchdog kicks in, or any other reset occurs (e.g. poweroff), there is nothing which can restore the bootvector (it remains in erased state, which is 00).

The easiest and safest way to "revive" the chips is to get access to parallel programmer capable of programming these chips (you can try some local programmer vendors, they sometimes provide chip programming as a service, or you can simply try to "talk them" into reprogramming a few of your chips).

With some hints from the 8052.com forum I have experimented with a "bootvector restorer" run from external program memory and I succeeded. However, I had only a P89C51RD2Hxx chip (mind the H in the suffix), which is an older revision than the H-less. So, if you are interested and wish to experiment, drop me an email, I'll send you the details.

Jan Waclawek

> Is it a problem with the bootvector?

It sounds so.
Do you use the "erase all" option?

Jan Waclawek

PS. Do you have a board where you could run the controller from external program memory?



Post Edited (06-27-06 00:15)

Have a better look at VPP/EA in schematics in AN461 - it is not just connected to GND via a capacitor - it IS connected to VCC (so the capacitor is only for decoupling).

Jan Waclawek

Maybe the problem is in hyperterminal - isn't the HW handshake on?
Hyperterminal has a bad reputation because of the overcomplicated way how to set it up. Try perhaps an alternative terminal program, my favorites are "Tera term" and "terminal by Bray".

Jan Waclawek