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Unknown microcontroller

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Daniel Ribeiro

New Member
Hi!
I've a microcontroller board on which the micontroller's identification was sanded and I would like to identify it.
The microcontroller's case is a TQFP44 or LQFP44
Analysing the PCB's electrical links, I see that :
The crystal, whose rated frequency is 11.0592 MHz, is attached to pins 30 and 31 of the microcontroller.
The microcontroller is powered with +5V ( pin 7 or 28 ) and GND ( pin 6 or 29 )
It has an I2C interface at pins 37 ( SCL ) and 42 ( SDA )
The PCB has a spare connector, which I think is used for programming the chip on board, whose
pins are connected to pins 14, 15, 16, 17 and 18 of the microcontroller.
Any help will be much appreciated.
Thanks in advance.
 

ronsimpson

Well-Known Member
Most Helpful Member
Looks like a hard job to me.
The last time I used a 11.0592 crystal it was on a 8051/8052.
good luck.
 

jpanhalt

Well-Known Member
Most Helpful Member
Can you give a little insight into why you need to know the MCU's identity? Isn't it the program that matters most?

John
 

atferrari

Well-Known Member
Microchip 44 pin TQFP series PIC16F87XA
Would you mind telling how can you be so precise on the chip ID? Interested.
 

vtech

Active Member
Would you mind telling how can you be so precise on the chip ID? Interested.
No problem. Part of my job at work involves finding & purchasing discontinued parts for internal use.
On going practice in mastering the use of search engine is what I do(ie google).
Let me be more precise;
The OP is asking for a specific criteria regarding a micro controller chip with very specific pin numbers w/related functions. Using the Boolean method, you will be surprised at the results of the spider engine.
It may take a while to recognize to weed thru returning results but it works every time.
 

Daniel Ribeiro

New Member
ronsimpson : me too :)
jpanhalt : I don't care about the program. I would like to use only the hardware, if the microcontroller were one that I know to program.
atferrai : See answer to vtech below.
vtech : You got it ! Based on your hint, I'm almost sure it's a PIC16F874A / PIC16F877A - 44-Pin TQFP.
It's a very interesting board. It has 8 opto isolated digital inputs and 8 relay outputs, alongside with a 24C64 serial EEPROM.
Once it came for free, I thought I could use the hardware to have some fun writing code to it.
Unfortunately, Microchip's PIC aren't my prefered processors. I think I'll donate it for a friend that has been programming
PICs for a long time. Thanks a lot.
 

atferrari

Well-Known Member
No problem. Part of my job at work involves finding & purchasing discontinued parts for internal use.
On going practice in mastering the use of search engine is what I do(ie google).
Let me be more precise;
The OP is asking for a specific criteria regarding a micro controller chip with very specific pin numbers w/related functions. Using the Boolean method, you will be surprised at the results of the spider engine.
It may take a while to recognize to weed thru returning results but it works every time.
Could show an example ?
 

jpanhalt

Well-Known Member
Most Helpful Member
While a front-door parametric search may not give all returns for 44 pins, searches for TQFP do return other options that meet the TS's criteria, such as the 16F1938/9 and 16F884/7 . All of those have the same pinouts for the pins described. There may be others, but the search is tedious.

John
 

Ian Rogers

User Extraordinaire
Forum Supporter
Most Helpful Member
While a front-door parametric search may not give all returns for 44 pins, searches for TQFP do return other options that meet the TS's criteria, such as the 16F1938/9 and 16F884/7 . All of those have the same pinouts for the pins described. There may be others, but the search is tedious.

John
Now it can be assumed a pic! A quick connection with a pickit2/3 will deduce exactly which one.... I think more than several pic18's also use that footprint!
 

jpanhalt

Well-Known Member
Most Helpful Member
Yep, now I am fully awake. Unfortunately, finding the Microchip list of device ID "devid" can be difficult, but there are some approaches listed here: http://www.microchip.com/forums/m466275.aspx .

For the TS, he might try erasing the chip, then see it if can be programmed. If he gets that far, then he can get the chip's hex ID.

John
 

Daniel Ribeiro

New Member
Folks : As I'll donate the board, it'll be left to the one that will receive it the task to discover what chip exactly it is. But now we know it's a Microchip's PIC.
But I'd like to thank to everybody in this thread, because I learned a lot with it.
 
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