Nissan ECU Tuning

b18onboost · Joined: 26 Dec 2004 Posts: 42

Could you someone tell me the starting address and ending address in hex for a rom dump via Datascan for Nissan Sr20det S13 ecu OBD 1

b18onboost · Joined: 26 Dec 2004 Posts: 42

FAST-TRACK · Joined: 21 Apr 2004 Posts: 165

Start 0000
end 7fff

Very Happy

hottroc · Joined: 14 Mar 2005 Posts: 113 Location: UK

xga · Posted: Sun Mar 20, 2005 10:55 am Post subject:

S14, S14a and S15 ECU's are 512 kilobits or 64 kilobytes in size. Therefore the starting address for these ECU's in hex is 0000 and the ending address is FFFF. Make sense?

S13 ECU's are 256 kilobits or 32 kilobytes in size. Starting and ending address in hex is 0000 to 7FFF.

hottroc · Joined: 14 Mar 2005 Posts: 113 Location: UK

Ahhh, that explains it. Thanks for your help.

Does that mean they use a different chip then? Ie is it a 27C512 instead of a 27C256?
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S14a UK spec 200SX
Various mods

PhatBob · Posted: Sun Mar 20, 2005 10:02 pm Post subject:

It seems like the daughter boards use 2x 27C256 (or 29C256)

hottroc · Joined: 14 Mar 2005 Posts: 113 Location: UK

2 chips, does that mean 2 lots of soldering and desoldering then? Or do I only need to replace one of them? If so, how do I tell which one?
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S14a UK spec 200SX
Various mods

PhatBob · Posted: Sun Mar 20, 2005 11:10 pm Post subject:

From what I've seen with the S14's you solder in a daughter board that has two chip holders. But I've just seen Badbiki's USB flash rom programmer and I think I'll get a couple of those to be honest.

b18onboost · Joined: 26 Dec 2004 Posts: 42

PhatBob · Posted: Wed Mar 23, 2005 9:43 am Post subject:

maxi_sss · Joined: 19 Dec 2005 Posts: 1 Location: Brisbane, Australia

I have a 1992 N14 Pulsar SSS (SR20DE, Australian Model) & have downloaded the ROM using DataScan...

I've downloaded 0000 to FFFF and when looking at the file in WinHEX, the majority of the data from 0000 - 7FFF (mainly from about 3000 - 7FFF) consists of large blocks of the same byte, repeated over & over. (eg: 3F 3F 3F 3F 3F, etc)

I am assuming that this is normal, as this would be a dump of the MPU's RAM, etc... correct???

also, is the MPU used in the N14 a 6303? (I am also wanting to run it thru a disassembler, but I know which to use until I know what MPU is used) I've had a little bit of exposure to assembly but have never tried disassembling anything before... but if someone can just point me in the basic direction that I need to head, I'm happy to give it a go from there.

thanks,

Maxi

Willy · Posted: Tue Feb 21, 2006 11:40 pm Post subject:

It's not a 6303 MCU, but a MELPS MCU.

There is a disassembler available and someone has written a disassembler helper program that makes it very straigh forward.

Check out this forum:

http://eccs.hybridka.com/

RomChip200 · Joined: 27 Nov 2003 Posts: 196 Location: France

There's a diff beween reading the EPROM on an EPROM reader and extracting the dump though Consult or what you want.

Reading :
S13 CA18DET : 0x0000 - 0x3FFF (16KB of code/data)
Z32 : 0x0000 - 0x7FFF (32KB)
S14, S15 : 0x0000 - 0xFFFF (64KB)

In the ECU, the adress decoder makes see the EPROM code/data at offset 0x8000.
In 0x0, depending on ECU, there's some RAM available, 128 bytes typically.
And 0x1000, 0x2000 (...) there're some input/ouput ports, ADC and so on.

Extracting :
S13 CA18DET : 0x8000 - 0xBFFF
Z32 : 0x8000 - 0xFFFF
S14, S15 : never done
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200SX CA18DET S13 '92.
300ZX TT '91.

speedlab · Posted: Mon Mar 17, 2008 2:37 am Post subject:

So how do you actually read the file? Mine reads, but won't save anything!
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