CPU Strangeness
Posted: Sat Apr 27, 2019 4:58 pm
I currently have 2 'dev' boards that I use for various test and beta hardware projects, The came to me as bare boards, so I wasn't so worried about using them for this function.
The first board, a C103253 is a bit odd in that it has SMT RAM, but otherwise a sound board, and I removed the CPU so I could fit a socket and use it for testing my PAK build, and subsequently the IDE interface we're testing right now.
It has this CPU:
The second board is a CO70789 REV D. Since I wanted to test the IDE interface on another board, I removed the CPU from this board too, and fitted a socket here too.
It has this CPU:
Now here is where it get's odd.
Since the IDE board already had the CPU from the C103253 already fitted to it, and not wanting to start prying the CPU out of the IDE board, I figured I'd plug it straight into the CO70789. When I powered on, it was like the board had no CPU installed!
At first I though it was something I'd damaged during the socket installation, so I ended up removing the IDE board, and the CPU from the IDE board.
At this point I had the CPU from the C103253 in my hand, so I plugged it into the CO70789, thinking nothing of it. Still the same, it was like there was no CPU installed.
WTF!
So I pulled the C103253 CPU from the CO70789 board, and fitted the original processor back in. Lo and behold it powered on just fine.
I then pulled the CPU from it's socket, fitted it to the IDE board, plugged it back in and all good.
So basically, my CO70789 board would not work with the CPU from the C103253 board.
So it seems there are differences between the two processors, though what they are I don't know. Well, yet at any rate, I'm definitely going to have a look later!
The first board, a C103253 is a bit odd in that it has SMT RAM, but otherwise a sound board, and I removed the CPU so I could fit a socket and use it for testing my PAK build, and subsequently the IDE interface we're testing right now.
It has this CPU:
The second board is a CO70789 REV D. Since I wanted to test the IDE interface on another board, I removed the CPU from this board too, and fitted a socket here too.
It has this CPU:
Now here is where it get's odd.
Since the IDE board already had the CPU from the C103253 already fitted to it, and not wanting to start prying the CPU out of the IDE board, I figured I'd plug it straight into the CO70789. When I powered on, it was like the board had no CPU installed!
At first I though it was something I'd damaged during the socket installation, so I ended up removing the IDE board, and the CPU from the IDE board.
At this point I had the CPU from the C103253 in my hand, so I plugged it into the CO70789, thinking nothing of it. Still the same, it was like there was no CPU installed.
WTF!
So I pulled the C103253 CPU from the CO70789 board, and fitted the original processor back in. Lo and behold it powered on just fine.
I then pulled the CPU from it's socket, fitted it to the IDE board, plugged it back in and all good.
So basically, my CO70789 board would not work with the CPU from the C103253 board.
So it seems there are differences between the two processors, though what they are I don't know. Well, yet at any rate, I'm definitely going to have a look later!