<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
<META NAME="GENERATOR" CONTENT="GtkHTML/3.0.10">
</HEAD>
<BODY>
I am debugging flash driver for MPC8555CDS board. The driver is drivers/cfi_flash.c. I have two boards. One is rev 1.0, with AM29LV641D. The other is rev 1.1, with AM29LV641M.<BR>
<BR>
The problem is polling DQ6 after programming. The current driver in U-boot 1.1.2 works well for AM29LV641M. As for AM29LV641D, the programming hangs after writing about 13KB. I track it down to "flash_is_busy()" function. When the problem occurs, the DQ6 keeps toggling. If I change the algorithm to polling DQ7, no problem occurs.<BR>
<BR>
Shawn has a similar problem <A HREF="http://lists.infradead.org/pipermail/linux-mtd/2004-March/009402.html">http://lists.infradead.org/pipermail/linux-mtd/2004-March/009402.html</A>. Maybe we should use DQ7 rather than DQ6.<BR>
<BR>
Another issue is the CFI driver might not work for all CFI compatible flash. For example, Micro MT28F640J3. Micro uses status register instead of DQ# polling. Somehow, we still need board specific driver.<BR>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%">
<TR>
<TD>
<PRE>--
Best regards,
York Sun, Ph.D
Metrowerks
Freescale Semiconductor Inc.
Phone: (512) 996-5252
Email: yorksun@freescale.com
This email, and any associated attachments have been classified as:
[x] Freescale Semiconductor General Business
[ ] Freescale Semiconductor Internal Use Only
[ ] Freescale Semiconductor Confidential Proprietary</PRE>
</TD>
</TR>
</TABLE>
</BODY>
</HTML>