public inbox for u-boot@lists.denx.de
 help / color / mirror / Atom feed
From: Remco Poelstra <remco.poelstra@duran-audio.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] Strange data behaviour
Date: Tue, 17 Feb 2009 12:55:36 +0100	[thread overview]
Message-ID: <499AA5B8.7030805@duran-audio.com> (raw)

Hi,

I'm trying to get my LPC2468 based board to work. I've some problems 
with the external memory databus.
I would like to know the settings of internal registers to see whether 
I've initialized them correctly, so I tried making a function that 
prints the content over the serial link. I'm still in the lowlevel_init 
function, so I do not have the U-boot puts functions available.
I wrote the following function to convert a long to a HEX string:
-------------------
void print_long(unsigned long data) {
   char i;
   char 
hex_data[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};

   for(i=0; i<8; i++) {
     while((U0LSR & (1<<5)) == 0); /* Wait for empty U0THR */
//    U0THR = hex_data[(0xDEADBEEF>>i*4)&0xF];
     U0THR = hex_data[(0xDEADBEEF>>4)&0xF];
   }
}
---------------
When I run it likes this I get 8 E's. Which is what I expect. When I run 
it with the commented-out line, I get back 8 0x0's. So it seems that the 
output is only correct when it is constant.
Does anyone have a clue on why that is?

Kind regards,

Remco Poelstra

             reply	other threads:[~2009-02-17 11:55 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-17 11:55 Remco Poelstra [this message]
2009-02-17 19:12 ` [U-Boot] Strange data behaviour Wolfgang Denk
2009-02-18  8:19   ` Remco Poelstra
2009-02-19  0:32     ` Kim Phillips

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=499AA5B8.7030805@duran-audio.com \
    --to=remco.poelstra@duran-audio.com \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox