[U-Boot-Users] [slightly offtopic] IDE interface for MPC823?

Udi Finkelstein u-boot-users at udif.com
Thu Jan 15 00:41:23 CET 2004


I apologize in advance. I know this is slightly offtopic here, but I think
this mailing list is the closest I could get to finding someone who can answer
this:

I'm looking for a schematic drawing showing how to build an IDE interface for
the MPC823. I have an existing board I want to hack an IDE interface to.

I've been seaqrching the net for boards that contains an MPC823 with an IDE
interface, but I couldn't come up with either an appnote, or an existing
schematic. (I found a block diagram of the terrapin mine, but it wasn't a full
schematic, and anyhow the IDE interface is implemented there using an FPGA).

I understand I must buffer the data bus (what type of 74xxx245 can I use? HC?
HCT? something else? IIRC the IDE bus works on +5V, while the MPC823 works on
3.3V.

The PIO part seems relatively easy (I either sacrifice 2 chip selects or
generate them from 1 CS using discrete gates I guess). What about DMA?

thanks,
Udi





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