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From: Scott Wood <scottwood@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] about nand_read_byte() interface
Date: Fri, 30 Oct 2009 11:42:19 -0500	[thread overview]
Message-ID: <20091030164218.GA631@loki.buserror.net> (raw)
In-Reply-To: <COL117-W144312DE78A03A66826082EEB60@phx.gbl>

On Fri, Oct 30, 2009 at 01:20:58PM +0800, HeLei wrote:
> 
> Hi, all

Hi, please wrap your lines at 75 or so characters -- and definitely don't
paste code as all one line.

> I'm a little confused on NAND read operation. 
> According to NAND character, NAND flash is read page by page, which mean's
> once you read, at least you should read data with page size (such as
> 512Bytes)

Yes, unless you're reading from the out-of-band area.

> But the nand_read_byte() is implemented as following:	static u_char
> nand_read_byte(struct mtd_info *mtd) { struct nand_chip *this = mtd->priv; return readb(this->IO_ADDR_R); }
> it seems only one byte is read out.

It's reading one byte out of a buffer that was previously filled with some
operation.  It is used for reading status bytes and OOB bad block markers.

-Scott

  reply	other threads:[~2009-10-30 16:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-30  5:20 [U-Boot] about nand_read_byte() interface HeLei
2009-10-30 16:42 ` Scott Wood [this message]
2009-11-02  3:07   ` HeLei

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