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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>file system cache problem on LPC1788</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/32276/file-system-cache-problem-on-lpc1788</link><description> 
LPC1788 with SDHC card attached using 4 data lines, e.g. not SPI.
I&amp;#39;m using MDK-PRO 4.60 and my project is RTX based. I&amp;#39;m using
networking and the RL-filesystem, with MCI_LPC177x_8x as my memory
card driver. 

 
When &amp;quot;File System Cache&amp;quot; is enabled </description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: file system cache problem on LPC1788</title><link>https://community.arm.com/thread/82181?ContentTypeID=1</link><pubDate>Tue, 07 Oct 2014 13:35:15 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:55876682-5101-4cf1-b253-4e3985d8fcb7</guid><dc:creator>Jamieson Olsen</dc:creator><description>&lt;p&gt;&lt;p&gt;
On the 1788 there is the main 64kB ram block, then two 16kB
&amp;quot;peripheral&amp;quot; ram areas. I&amp;#39;ve found that I needed to push the EMAC
into this peripheral area in order to get the network to run.&lt;/p&gt;

&lt;p&gt;
Relocating the File System Cache into either of the peripheral ram
areas doesn&amp;#39;t seem to have any effect.&lt;/p&gt;

&lt;p&gt;
In Summary:&lt;/p&gt;

&lt;p&gt;
FS cache enabled: large file writes to the SD card (via FTP) fail
and I get zero (or very small) length files written instead. Reading
large files from the SD card works fine.&lt;/p&gt;

&lt;p&gt;
FS cache disabled: large file writes to the SD card work, but
slowly. Reading files from the SD card is fine.&lt;/p&gt;

&lt;p&gt;
I&amp;#39;ve also tried slowing down the SD_CLK speed and/or increasing
some of the TOUT values in MCI_LPC177x_8x.h -- no change.&lt;/p&gt;

&lt;p&gt;
The problem appears to be in the MCI driver, WriteBlock routine.
The MCI peripheral status word comes back 0x0000 0002 --
DATACRCFAIL.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: file system cache problem on LPC1788</title><link>https://community.arm.com/thread/68912?ContentTypeID=1</link><pubDate>Tue, 07 Oct 2014 11:37:41 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:28f5baff-5e5c-4a0d-a286-266a96b04e65</guid><dc:creator>ImPer Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
I haven&amp;#39;t worked with DMA on the 17xx chips, but the 23xx chips
have multiple separate RAM blocks and doesn&amp;#39;t allow DMA transfers for
the 32kB of main RAM to dedicate the full memory bandwidth for the
processor core. The secondary RAM blocks are on a separate bridge
together with the peripherial hardware and supports DMA.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>