Messages

[V]

Erik,

are you sure you are referring to the P89V51RD2?

JW

There is nothing special in reset circuit design for entering the bootloader using the "V", it's just the RS232 level convertor only for Tx and Rx - you run FlashMagic set to the "V" device, that will start sending "U"s, then you reset the mcu which waits at the beginning for the "U"s and if it sees them it enters the bootloader mode - and that's all. You don't need to fiddle around with /PSEN as it was with the "C" device.

If this procedure is not suitable, e.g. if there is a continuous serial stream on the UART even while resetting is possible in the final application, the bootloader can also be customized if needed, so that it enters the bootlader mode upon a different condition (e.g. some pin set) - but that needs reprogramming the bootloader.

Jan Waclawek

I hope it's clear for you how it works - your program has to set the EBRR bit; then upon reception of the break signal (i.e. a "zero" on the Rx pin for longer than one character time) the LPC9xx will automatically reset to the bootloader. If you are sure that break cannot occur spuriously, it is perhaps not a bad idea to enable it immediately after reset... (but if you are sure in what you are doing, do it your way).

Hyperterminal is quite a dumb terminal program and it's only advantage is that it is readily available on almost all computers with Win (so one does not need to carry it around e.g. at the customer). Try TeraTerm (Control->Send break (AltB); or try http://realterm.sf.net - the latter has good features for the RS232 lines' control, but the program itself has a little bit messy look... (and a bug when transmitting files, but that's not what you need now).

Jan Waclawek

Parvez,

Sometimes you might just need to retry - depending on the combination of crystal frequency, RS232 level convertor+cable (delays and distortions) and the baudrate the autobaud process can sometimes kick in at a different frequency.
However, you might try to go down with the baudrate and that generally helps - try perhaps as low as 1200 bauds.

Jan Waclawek

I wrote this because the same happened with me.

The programmer (LabProg48 by www.elnec.sk) SUPPORTED the P89V51RD2 and programmed/erased etc. it very well - until the SoftIce mode in bootloader version 4 was engaged. First I suspected problems in the chip, but after asking them, they discovered the problem (I don't know the details but they said a particular signal sequencing has to be implemented) - and offered me an immediate interim upgrade, as they have planned software upgrades monthly.

Of course the software upgrade was free, but I believe it is the standard today for parallel programmers.

Jan Waclawek

http://www.efton.sk/t0t1/unsoftice.htm

You should also complain at the manufacturer of you parallel programmer, this is a result of a flawed programming algorithm of the programmer.

Jan Waclawek

The autobaud routine works so that it waits for one edge of the incoming signal ('U' character) using jb, starts timer2, waits for another edge using jnb, stops timer and calculates the reload value based on the measured bit time (maybe the jb and jnb are the other way round but that does not matter here).
Depending on the ratio of oscillator/timer ticks to bit time, it might make one more or on less jb or jnb, hence the reload time might be a little off. This happens with a certain probability again based on the particular oscillator to bit time ratio and can be calculated. See http://www.efton.sk/t0t1/autobaud_error.htm for more details - there is also an xls sheet where you can try your settings (by the way, what is your crystal value?)

So what I think could happen is that at 7200 baud the autobaud sometimes results actually in around 7000bauds; and while the "real COM port" (the UART behind it) might be tolerant for the error (it is below 3% so it might be good, although marginal), the FTDI chip might be not, or the RS232-to-5V level convertor used with the FTDI chip might distort the signal enough to get outside the acceptable error margin.

Jan Waclawek

Try to find out the brand of the CHIP used in your USB-COM "cable" (not the "brand" of the cable). Some chips are flawed.

http://www.8052.com/forum/thread.phtml?thread=97853

Jan Waclawek

:0000000BF5

It's right there at the end of ISP commands table... Always download the latest datasheet! (it was missing in datasheet rev.1 but the current is rev.3)

I have prepared also a more complex table containing the ISP and IAP commands for various ISP-able '51 derivatives, maybe it might be of some help: http://www.efton.sk/51comp/rd2comp.htm (the excel original is at the end of the table, you can make an excerpt just for the V51).

Jan Waclawek

[serial number is in use]

P89V51RB2_RC2_RD2-03.pdf, 7.2.5 Using the serial number, page 25:

If the serial number is in use, reading, programming, or erasing of the user code memory or the serial number is blocked until the user transmits a

I would expect that even for full chip erase via ISP, entering the correct password first is necessary.

Jan Waclawek

> I want to reprogram boot block. How to do.

I don't know, I don't have an ALL-11. Refer to the ALL-11 manual.

Jan Waclawek

> That command resets the device.

Andy, do you mean the same way if the RESET pin would be pulsed high?
I tried it with P89C51RD2H, it does not work like that.

Jan Waclawek

This is an ISP-programming forum, with general questions on '51s better go to http://www.8052.com/forum .

Nevertheless your questions might be answered in the 8052.com tutorial, and/or the "bible" ( = 8051 manual). The datasheet usually deals only with the items which are different from the "classic" 8051 and are specific for the given model.

Jan Waclawek

Of course if you erased block 1 containing the bootloader you cannot run it...

But you mentioned you used ALL-11 to erase it - so it IS a parallel programmer, isn't it - if it is capable of erasing the boot block, it should also be able to program it, check it out.

Jan Waclawek