Subject: Re: Expantion port details
To: Sarah <g@SDF.LONESTAR.ORG>
From: Marcus Comstedt <marcus@mc.pp.se>
List: port-dreamcast
Date: 05/07/2002 00:45:19
Sarah <g@SDF.LONESTAR.ORG> writes:

> Tell me, did I miss details about how the port is mapped in memory through
> those links or is there a description somewhere aside from 'yeah, it's
> just at this address'? is the port slower then the bus? are there some
> timing issues?

As I understand it, there are severe peculiarities involved, such as
multiplexing of the wires (a 32 byte write would be something like
AD0-AD15 = address, then AD0-AD15 = half of the data word, and then
AD0-AD15 = other half of the data word).  I don't know if anyone has
made a formal documentation of this.


  // Marcus