[LinuxBIOS] alix and Artec LPC dongle [was: LPC.1A adapter?]

[Peter Stuge]

On Wed, Dec 05, 2007 at 05:17:19PM -0500, Ward Vandewege wrote:
> The alix.2/3 manual mentions that port J11/J16 can be used for an
> alternate flash rom via an LPC adapter. The alix.1 manual describes
> the same on port J16. 
> 
> The PC Engines adapter LPC.1A is mentioned in this context, but I
> can't find any documentation about it, not even on their website.

It's on the website but not linked, so you have to guess the
filename.


> Ron, which adapter do you use? Would the one that comes with the
> programmable LPC dongle by the Artec Group work?

Yes, Artec's LPC dongle works with the alix1c.

I'm using the previous product revision 441103 but there's no reason
the current revision 441104 should not work equally well or better.
(Allow longer cabling.)

It needs a cable with pins connected the right way, but no other
components are needed.

I hacked the proper cable up by cutting up an old floppy cable and
pressing a 10-pin header onto one end. This is my wiring diagram:

alix1c J16
  LCLK0  1  2 GND
   LAD0  3  4 GND
   LAD1  5  6 GND
   LAD2  7  8 GND
   LAD3  9 10 GND
LFRAME# 11 12 GND
PCIRST# 13 14 NC
  CSEXT 15 16 VCC5
    GND 17 18 VCC3
 SERIRQ 19 20 LDRQ#

441103 J3
 PCIRST 1  2 LAD0
   LAD1 3  4 LAD2
   LAD3 5  6 LFRAME#
R330GND 7  8 PCICLK1
    GND 9 10 VCC3 in

441103-alix1c:
1-13 2-3 3-5 4-7 5-9 6-11 8-1 9-2/4/6/8/10/12/17 10-nc -15/18

441103 pin 9 connects to any one of the alix1c pins, not all of them.

The last one, -15/18 means that pins 15 and 18 on the alix1c end
should be connected together, but not to any pin on the dongle end,
in order to pull CSEXT to 3.3V and tell alix to boot from LPC flash.

(Too bad CSEXT isn't active low, then it would just have been a
jumper on the header on the board. Oh well. :)

The alix1c docs don't say if CSEXT is 5V or 3V so I played it safe
and tried 3V first, which works.

My cable length is ca. 10cm. The LPC dongle docs say that cables
should be kept to just a few cm but 10cm works fine for me.

Note that the above cable can supply power to the LPC dongle. Pay
attention to JMP4 on the dongle or the alix power supply will be
connected to the USB host power supply that the dongle is connected
to. May or may not be a big deal depending on the power supply
designs.


//Peter