CXD9764GP

[martravi]

The CXD9764GP IC is marked as "SPEED" on the mainboard picture. However, SPEED is the CXD9731GP, which in the case of XPD-005 consoles is located on the small daughterboard that also has the Altera FPGA. On XPD-001 consoles, it's located above MECHACON on the EE+GS side of the board.

I don't know what the CXD9764GP does, probably provides an IDE interface for DVRP and/or does hardware de-/encryption stuff?

[DiscoStarslayer]

This is a good point, however, it appears CXD9731GP and CXD9764GP share the same bus from the IOP. I've verified this with some very quick continuity tracing on a XPD-002, but not 100% with a full board traceout or confirmation on an XPD-001.

My current assumption is both devices are SPEED devices, and they share the bus using some kind of chip select, but this is all theory and I'd be happily proven wrong.

It is very likely that the CXD9764GP performs the encryption of the data stored on the IDE, as we haven't found a lot in the DVRP firmware to suggest it's performing the encryption outside of checking the security string using sony specific ATA commands.