I bought a docking station a bit back and tore it down; I'm not very impressed but I'm sure we can make something of it.
Connector and IR:
Connector - Top:
Connector - Bottom:
Mainboard - Top:
Mainboard - Bottom:
As you can see on this unit there isn't any HDMI however the board was made for it. Also of note is the HDMI pins on the ribbon cable.
I've checked and the nuvoTon (W78E052DFG) is an 8052 with 8KB flash and 256 bytes ram.
The audio portion seems to have a filter set on it however I don't believe it's amplified.
I have not been able to determine if there is or isn't USB on the ribbon cable or connector though there's no sign of it on the board.
Another point is I've switched to a custom rom and it no longer detects the dock. I noticed before switching that there is a service that watches for the dock and I'm guessing sends a signal to android to start the media app on dock. Virtuous XooM does not in any way detect connection.
Communication with the 8052 is through serial and the kernel source shows info about it. I haven't been able to find any reference to USB. if USB is present I'd expect it to be the pair near pin 30.
(All images taken with the A500 camera)
------- New info: (copied from later post)
This is the dock pinout as seen by the tablet (other devices may have different pins connected)
1-10 no connection
11 - unknown - traced to Q9 near IR connector on dock but unable to find past there (2v from tablet)
12 no connection
13 - audio connect of some sort - appears to be connected to left channel (after capacitor) through a 1k resistor
14 - Right audio - decoupled with 100uF
15 - Left audio - decoupled with 100uF like right channel
16 - Audio ground - not connected to main ground
17 no connection
21-30 HDMI - NO signals connected except GND at 21,24,27,30
31 - unknown - 3.3v from tablet
32 - TXD pin on 8052 through a level converter
33 - RXD pin on 8052 through a level converter
34 - unknown - 0v - 3.3v when dock unpowered but tablet connected so this may be a dock detection
35 - connected to 33 on tablet side
36 - connected to 32 on tablet side
37-40 no connection