RE: [ECOS] PCMCIA Standard CIS access

["Lewin A.R.W. Edwards" <larwe at larwe dot com>]

>My particular controller requires that I set an "Enable" bit in order to
>make a card access.  I'm assuming this includes a Attr/CIS type of card
>access.  Anyhow, it doesn't seem to matter what I do, whenever I enable
>this bit, it locks the program until I eject the card.

How far does it get? If this lockup wasn't cleared by ejecting, I'd guess 
the PCIC is generating an interrupt that kills the OS, but since it is 
cleared by ejecting the card, it sounds like your code has got to a point 
where it's polling continuously for some state. Trace, trace, trace :)

The enable bit _probably_ enables the output drivers on the buffers that 
drive the control, address and data buses. If there is no specific mention 
of power control then it might be handled externally.

>Also, when you say LVD2 and LVD1, I assume you mean the two pins that
>are for voltage selection, correct?  If so, mine are VS1 and VS2.  VS2

Yes.

>is set which must mean 5V since that's what the card is.  VS1 is also
>set, but I don't know what it represents since the documentation says it
>differentiates between 3.3V and X.X-V cards.  But what does the X.X
>mean?  How can I possibly know what an X.XV is without a number?

Since I posted my last email to you on this subject (with the card init 
order), I happened to check one of my PCMCIA references (PCMCIA System 
Architecture) on something else, and it basically confirmed what I had 
paraphrased in that earlier message, except to say this:

"Vcc will always be 5V when the card is first accessed if the socket is 
based on the 2.x standard. In these systems, if the PC Card supports dual 
operating voltages (5V and 3.3V) the operating voltage will be reduced to 
3.3V during card initialization. Systems that support low voltage sockets 
determine the initial Vcc that is applied to the socket by sampling VS1# 
and VS2#. (VS1# and VS2# are not used in 2.x systems)"

I am mailing you the relevant chapter privately. BTW, since this discussion 
is hardware and not eCos-related, it might be better to move it to 
comp.arch.embedded or private email.


-- Lewin A.R.W. Edwards
Embedded Engineer, Digi-Frame Inc.
Work: http://www.digi-frame.com/
Tel (914) 937-4090 9am-6:30pm M-F ET
Personal: http://www.larwe.com/ http://www.zws.com/

"Far better it is to dare mighty things, to win glorious triumphs, even 
though checkered by failure, than to rank with those poor spirits who 
neither enjoy much nor suffer much, because they live in the gray twilight 
that knows not victory nor defeat."
(Theodore Roosevelt)