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Topics - Ram

#1
P89V51Rx2/P89LV51Rx2 / Unable to ISP P89V51RD2BN
July 14, 2009, 05:46:35 AM
Dear Andy,

We designed the attached schematic for P89C51RD2BN
(we call this board the "HMI board"). It is working
as we intended.

We connect the HMI board via MAX232 to the PC. We
have used various versions of Flashmagic. We are
currently using the latest version: 5.201717.
We are able to ISP the p89c51 by shorting pins 1 and
2 in JP1 (on the left hand side of the schematic).
Indeed, we have ISP-d the p89c51 maybe over a hundred
times and are pretty comfortable and happy with its
ISP feature.

About a year ago, we saw that the p89c51's were not
available in the market anymore. Instead, P89V51RD2BN's
were. So, we bought about 10 of the p89v51's.

We have been trying to ISP the p89v51's ever since.
But, we have not been successful yet. For testing that
our connections are alright, we first ISP the p89c51,
power off, remove the p89c51, do not make any
modifications in the circuit except removing the short
between pins 1 and 2 in JP1, and insert the p89v51 in
place of p89c51.

On the Flashmagic side, we do the following:

1. Uncheck "use DTR to control RST".
2. Set the following under Step 1: 89V51RD2, COM 1, 9600,
   None (ISP)
3. Check the following under Step 2: Erase blocks
   used by Hex File
4. Under Step 3: Select the hex file to be burned, say
   targetboard.hex
5. Under Step 4: check "Verify after programming"
6. Hit Start

Flashmagic says, "Reset the device into ISP mode now".
We either switch on the power to the board, or if it
was already on, then we press the reset button S2 in the
top left hand side of the attached schematic.
Then we hit the cancel button on the Flashmagic pop up.

The message disappears and nothing happens.


We have tried various other things:

1. We have burned the boot code available at
http://www.flashmagictool.com/assets/resources/P89V51Rx2_Bootloader_Update.zip using our universal programmer.

2. We have also burned the boot code available at
http://www.nxp.com/files/products/standard/microcontrollers/utilities/p89v_lv51rd2_bl_upd_v5.zip using our universal programmer.

We took care to burn these codes in Block 1 of the
p89v51.

3. We tried all the baud rates less than or equal to 9600.

4. We used a terminal program (equivalent to Hyperterminal)
and sent out "U" characters to the Rx pin of the p89v51, and
saw if we were receiving anything.

Here we noticed something interesting: nothing was coming
back to the terminal program from the HMI board.

But, when we tried a different (bare bones) board that
contained only the MAX813L, with the pushbutton for manual
reset, a 11.0952 MHz crystal with its capacitors, and the
Rx and Tx pins brought out to our MAX232, then we had U's
coming back to our terminal program in response to U's sent.
When Vdd was 4.96 V on the bare bones board, we had the
returning 55's (hex for U) interspersed with some FF's, while
for Vdd above 5.05 V, we had only 55's. Even when we have
only 55's returning, we are unable to enter the ISP mode.

Of course, we need to further investigate this difference
in behavior between the HMI and the bare bones boards.

Do you notice anything in our HMI board's schematic that
would prevent the p89v51 from entering ISP mode?

There is one another question: On our universal programmer,
when I load the boot code's hex file that I downloaded
from flashmagic's site, I need to select the file format
from several options presented to me under "auto format
detected". Two options seem to be most relevant to this hex
file --- "intel" and "intel hex 16". I have been selecting
the first one assuming that your hex file is an intel hex 8
file. Please let if my choice was correct and if "intel"
means "intel hex 8". The documentation of the universal
programmer does not contain anything on this topic.

Thank you.

With best wishes,

Ram.