How to identify a microcontroller with unclear part number!?

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
Hello All,

I have been looking to identify a microcontroller that has two series of numbers (2 lines) and no manufacturer's logo, I know that one of this serial numbers dictates manufacturer's info and the other one is part number but I have searched both numbers on the internet with no luck what so ever!

Here are the 2 serial numbers:
C90832 (here I am not sure with the 3, it might be an 8 or a B but I tried multiple possibilities anyway!)
739U70K
Probably the package is QFP or LQFP with 32pi.

I am not sure but there is a huge chance this IC is chinese, what can I do to identify the microcontroller in this case!? or if anyone has ever dealt with this microcontroller or its family, can you guide me to a datasheet or something?

Regards,
 

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
Hello,

The part is likely an inhouse or OEM number.
As you said, nothing can be found on the internet.

Bertus
This microcontroller from an air-conditioner motherboard made by Midea Group "a Chinese home-appliances manufacturer" which I doubt it can make its own microcontrollers..but it could be from a local Chinese Semiconductor manufacturing company!
 

LesJones

Joined Jan 8, 2017
3,196
Even if you can buy a replacement microcontroller do you have the program code to write to it ? You would also need a programmer to write the code to the microcontroller.

Les.
 

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
I just need the microcontroller's reference so that I can extract (flash, ram, io, peripherals, ....) and then I ll try to find a similar microcontroller from a different manufacturer..or I will write my own code if this manufacturer provide enough support!
 

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
How will you extract data from the chip (a) if you don't know the pinout and (b) if the chip content is protected?
I used the wrong verb "extract" lol ...I mean if I know the part number of microcontroller I can get info like flash, memory, ram, num of IO, ... and other peripheras from datasheet that's all.
I know that I can't get the code already flashed in the microcontroller.
 

Papabravo

Joined Feb 24, 2006
16,195
This microcontroller from an air-conditioner motherboard made by Midea Group "a Chinese home-appliances manufacturer" which I doubt it can make its own microcontrollers..but it could be from a local Chinese Semiconductor manufacturing company!
Midea Group does not need to make their own microcontrollers. There are plenty of companies that will make a custom version of an existing design for a piece price, and throw in the NRE at no charge for a sufficiently large volume order. The other impediment is that the documentation is probably unreadable as well as unavailable. I think you're just SOL. Maybe the chaplain can punch your TS card.
 

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
Midea Group does not need to make their own microcontrollers. There are plenty of companies that will make a custom version of an existing design for a piece price, and throw in the NRE at no charge for a sufficiently large volume order. The other impediment is that the documentation is probably unreadable as well as unavailable. I think you're just SOL. Maybe the chaplain can punch your TS card.
You are totally right!
Most chinese semiconductor manufacturers base their microcontrollers on the 8051 architecture...
I've already had a hard time deciphering some sinowealth microcontroller's datasheet...and now I am stuck with this unknown mcu!
 

michael8

Joined Jan 11, 2015
137

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
Could it be:

https://lcsc.com/product-detail/NUVOTON_N76E003AQ20_C90832.html

Nuvoton Tech N76E003AQ20
Manufacturer Nuvoton Tech
Mfr.Part # N76E003AQ20
LCSC Part # C90832
Package QFN-20
Datasheet https://datasheet.lcsc.com/szlcsc/1811151525_Nuvoton-Tech-N76E003AQ20_C90832.pdf

Nuvoton Tech N76E003AQ20 Description
8-Bit FLASH 8051 16MHz 2.4V ~ 5.5V QFN-20 NUVOTON RoHS

Have you tried to trace out what the pins connect to and figure out what the micro is controlling?
LCSC Part # C90832 this looks the same but 20 pin !!?
As I mentioned before this mcu is used in an air-conditioner motherboard...
what I know so far about this mcu:
* package is QFP32 or LQFP32.
* pin 6 is VDD and pin 7 is VSS.
* pin 9 is SCL and pin 10 is SDA.
* pin 12 probably an interrupt (used for a zero-crossing detection).
* pin 28/29 used as ADC.
* most pins used as IO with uln2003.
I guess I'll have to go through Nuvoton/SinoWealth mcu catalogue and see if i can find something similar.
I have a strong filling that this mcu is a Sinowealth SH79F9204 ... correct me if i am wrong!
 

Thread Starter

Younes Thabet

Joined Jan 9, 2019
53
product link for SH79F9204:

http://www.sinowealth.com/detaile?pro_id=174

The "rar" link downloads a zip file (!) containing a pdf datasheet, The datasheet is chinese with
readable english notes near most things like pins.

Don't know if this is your processor. Could you just drive whatever the old processor did with your own
different processor and own code?
the placement of vdd and vss in SH79F9204 looks the same with the unknown mcu but in terms of other pins idk! I'll have to check again.
that's exactly what i am gonna do!!
thanks for your help mate.
 
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