public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "hacklu" <embedway.linux@gmail.com>
To: "linux-kernel" <linux-kernel@vger.kernel.org>
Subject: how to understand powerpc's BRx ORx
Date: Fri, 10 Sep 2010 09:53:10 +0800	[thread overview]
Message-ID: <201009100953083354338@gmail.com> (raw)

         I didn't understand the address mask.
it's said that: BR[BA] is the base address,the OR[AM] is the  address mask,
"Provides masking for corresponding BRx bits. By masking address 
bits independently, SDRAM devices of different size address ranges can be used. Clearing 
bits masks the corresponding address bit. Setting bits causes the corresponding address 
bit to be compared with the address pins. Address mask bits can be set or cleared in any 
order, allowing a resource to reside in more than one area of the address map. SDAM can 
be read or written at any time."

how to understand it?
for instance, if my BR0[BA]=0111_0000_0000_0000_0, OR0[AM]=1111_1111_1111
if I want to access the 0x70000000 or the 0x71000001.what address calculate will be taken?

thanks all
 				
--------------
hacklu
2010-09-10


                 reply	other threads:[~2010-09-10  1:53 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=201009100953083354338@gmail.com \
    --to=embedway.linux@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    /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