Please help - PSOP44-29F400BB - Reads ok to 0x8000

By: Gustaf - 2008-08-05 23:31:53

Hi!

I have a Willem 4.1 together with an Sivava PSOP44 adapter.

I am trying to read and program an AMD AM29F400BB-90SE but have some problem.

FACTS:
Using 0.97g and 0.97ja both with the same problem. No difference switching Temporary Sector Unprotect On/Off, Skip Write 0xFF on/off, and AAAA,5555.. on/off.

1. Electronic ID = OK

2. Reading works, BUT, the data is corrupt when compared to bin from other (correct) programmer. The data until 0x8000 is the same but after that the data is not the same.

3. I have redone all the soldering twice and measured all the connections with a multimeter.

4. Not using any additional cable over the ZIF32 (A19 not connected). Vpp to pin 1 not connected (N/C in 29F400).

The rom is from an Bosch ECU if that helps..
Please help, my electronics skills are not enough..

Kind regards // Gustaf

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: EZo - 2008-08-06 20:55:50

Quote:
The data until 0x8000 is the same but after that the data is not the same.

Are data from adress 0x8000 equal to content from adress 0x0000 ?
Check chip pins in socket, clean them. Attention to pins A14, A15 (pins 35 and 36). Check lines on adapter connected to mentioned pins.

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: Gustaf - 2008-08-06 22:51:30

EZo wrote on 08/06/08 at 20:55:50:
Quote:
The data until 0x8000 is the same but after that the data is not the same.

Are data from adress 0x8000 equal to content from adress 0x0000 ?
Check chip pins in socket, clean them. Attention to pins A14, A15 (pins 35 and 36). Check lines on adapter connected to mentioned pins.


Sorry for me being unclear, the data from 0x0000 to 0x8000 coincides with the original bin file (is the same as). So 0->8000 is OK. Thereafter portions of the data is corrupt.

I cleaned and resoldered all of the pins of my adapter and checked ALL of the connections from the ZIF32 pins of the adapter to the chip-pins using this as reference: (http://www.se-ed.net/mpu51/eprom/pdf/psop44.pdf). All were OK but:

The differences I found was that (RY/BY#) was connected to VCC on the Sivava adapter instead of VPP as in the PDF. And that CE#,Vss and Byte was connected to GND  _and_ to Vpp over a resistor (2k2). I tried desoldering the resistor but, NO difference.

Don't now what to do..

Kind regards // Gustaf

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: EZo - 2008-08-07 00:06:05

Quote:
Sorry for me being unclear, the data from 0x0000 to 0x8000 coincides with the original bin file (is the same as). So 0->8000 is OK. Thereafter portions of the data is corrupt.

My understanding - you are reading chip now , without erase and programming. Your read is different to source file (read from correct programmer) starting from adress 0x8000. If chip A15 is not getting logic 1 (shorts or other failures) buffer is starting get content from chip start adress. This is why I am asking - compare lines of bytes starting from adress 0x8000 and 0x0000. Do the same in source file (may be failure in read from correct programmer).
Have you tried chip erase and programming.
Quote:
The differences I found was that (RY/BY#) was connected to VCC on the Sivava adapter instead of VPP as in the PDF.

Chip pin 2 RY/BY schould be disconnected (for AM29F400). Allowed pin connection via resistor to Vcc. Pin 2 is connected to Vpp for chips 28Fx00 only.

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: Gustaf - 2008-08-07 19:33:33

EZo wrote on 08/07/08 at 00:06:05:
compare lines of bytes starting from adress 0x8000 and 0x0000.


Yes I am reading and getting data, comparing to _confirmed_romfile read from an professional burner.. -->

You are right ! The rom I read with the willem starts over again at 0x8000 and again at 0x10000... Does this mean that A15 is not being switched to logic 1 when passing to 0x8000?

I shall check A15 connection again, but I don't think there is an fault with the socket. What more tests can I do? Any software settings?

Thanks alot for your help!!

Kind regards / Gustaf

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: Gustaf - 2008-08-07 20:17:00

Update:

Seem to have found a fault.

I tracked A15 to ZIF32 A16 (willem side). Measured resistance and compared to others, ALL OK.

BUT... I used the test hardware (A0->A23 0xFFFFFF) function in Willem Eprom 0.97ja and mesured ALL of the adress channels. All were ok(4.9V+) EXCEPT A15-A18, they measured this:

A15 = 0.8v
A16 = 0v
A17 = 0v
A18 = 0.8v

What to do?


Kind regards // Gustaf

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: EZo - 2008-08-07 22:21:35

Check   line from IC4/10 to IC5/15 (A15), no shorts to GND or other line.
Check IC5/16 Vcc (+5V) -simply measure voltage pin 16 on all 4015.
You can find IC4 - go Test H/W , activate A14-29 and find 4015 with pin 3 +4.9V. Then go from IC4/10 and check.
Check is really DSW12/ switch 1   off , measure resistance.
In case of human mistake or DSW12/1 failure DSW switches 1 and 3 are/were ON, and Vpp was activated-   both chips IC4 and IC5 probably damaged and should be replaced.

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: Gustaf - 2008-08-07 23:05:41

EZo wrote on 08/07/08 at 22:21:35:
Check   line from IC4/10 to IC5/15 (A15), no shorts to GND or other line.
Check IC5/16 Vcc (+5V) -simply measure voltage pin 16 on all 4015.
You can find IC4 - go Test H/W , activate A14-29 and find 4015 with pin 3 +4.9V. Then go from IC4/10 and check.
Check is really DSW12/ switch 1   off , measure resistance.
In case of human mistake or DSW12/1 failure DSW switches 1 and 3 are/were ON, and Vpp was activated-   both chips IC4 and IC5 probably damaged and should be replaced.


Thanks again for the help, I will read your post more closely in the morning.  I checked the Vss and Vdd for all 4015 and they seemed ok. I then traced the Data line from 4015(1) to 4015(3) and found something strange.

When I came to 4015(3) arriving at Db i found a short between Db and O2b. That doesent seem right, does it?  I know there should be a short between O3b and Da for each 4015. But a short between Db and O2b sounds strange?

Kind regards// Gustaf

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: EZo - 2008-08-07 23:18:32

Check on w4.1 schematic.

Re: Please help - PSOP44-29F400BB - Reads ok to 0x

By: Gustaf - 2008-08-10 19:34:43

Thanks alot for all the help!

With the schematic as a help I could finish the fault seeking, and discover that this was a case of human error as usual =)

As I mentioned I found a short between Db and O2b on one of the 4015 drivers. After having a look on the schematic I discoverd that the O2b of that 4015 was in deed adress pin A15 and I hade probably found the problem. But why were there a short? --- Hmmm..

I had happen to forget that the last chip I programmed was a 29C256 which needs the "29C256 jumper" connected, and after looking at the schematic some more I found that it was actually shortening these pins... Fault found...


Thanks EZo for all help!  Kind regards // Gustaf