Topic: Tech Question About How It All Works (Read 42 times)

Mr Nobody · « **on:** March 22, 2004, 06:11:00 AM »

When is it ever good to connect or disconnect a wire while a device is ON?

Artifex · « **Reply #1 on:** March 22, 2004, 07:39:00 AM »

In a nutshell....

When the box boots, the cpu starts out by initially executing a "Stage 1 bootloader" stored in the MCPX unit. This bootloader, among other things, initializes hardware, and attempts to read 1 byte from the tsop. If this one byte is odd, it attempts to load a "stage 2" bootloader ("2bl") from there. If this one byte is even, it assumes that the image on the TSOP is corrupted, (hardware) redirects the flash access to the LPC, and continues from there.

So, when you tie the d0 (the low order bit of the data lines) to GND, it forces the tsop to always show an even number (low bit always 0).

Once the MCPX redirects the flash access to the LPC, there is no EASY way to send it back to tsop.

But, really... the big question... "Why would you even want to?"

--Artifex

dokworm · « **Reply #2 on:** March 23, 2004, 02:09:00 PM »

So no-one knows how to do it huh?
Guess I will jsut have to start playing

OVerlordI · « **Reply #3 on:** March 23, 2004, 06:13:00 PM »

Artifex said there is no EASY way to switch. it can be done. So yes people know how to do it

erexx · « **Reply #4 on:** March 23, 2004, 06:34:00 PM »

Author Topic: Tech Question About How It All Works (Read 42 times)