80c51 microchip weird clone?

Status
Not open for further replies.

neazoi

Advanced Member level 6
Joined
Jan 5, 2008
Messages
4,123
Helped
13
Reputation
26
Reaction score
15
Trophy points
1,318
Location
Greece
Activity points
36,955
hello I have found this picture **broken link removed**
I would like to know why this chip has pins that go through the ceramic to the other side.
Was this to accept an additional eprom or to connect it with another similar microcontroller in parallel or to program it without having to remove it from the board?
 

I think it was a bond-out version of the processor, either for making an in-circuit emulator or using external EPROM by making the address and datalines accessible.

Keith.
 
Reactions: MRAMA

    M

    MRAMA

    Points: 2
    Helpful Answer Positive Rating
this is a funny IC .. lucky that i am seeing it here..

Does this still exist , as i heard 80c51 IC s are obselete
 

Generally speaking the 8051 only has ROM (non-programmable). The 8751 had the EPROM. The connector is probably for a 28 pin EPROM that would allow for development with an EPROM while there is no internal ROM on this particular part. I have not seen this in an 8051 variety that I can remember, but I actually have a National Semiconductor version of the 8048 (predates the 8051) with this feature. It actually came with jumpers to allow the use of a 2716 ( 2Kx8 ) which was a 24 pin part or a 2732. I am sure there were similar approaches to some other micros, I seem to remember the Z8.
 
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…