Re: [lwip-users] missing TX packets

[Lehel Benedek]

Hi Marty,

I know that the max recommended setting for the EMC clock is 80MHz.

Unfortunately I am limited on my board to a 16 bit data-bus to SDRAM, however I ran extensive comprehensive memory tests at that higher frequency, and everything seems to be OK.

On Thu, Jan 9, 2014 at 1:00 AM, <address@hidden> wrote:

Send lwip-users mailing list submissions to
        address@hidden

To subscribe or unsubscribe via the World Wide Web, visit
        https://lists.nongnu.org/mailman/listinfo/lwip-users
or, via email, send a message with subject or body 'help' to
        address@hidden

You can reach the person managing the list at
        address@hidden

When replying, please edit your Subject line so it is more specific
than "Re: Contents of lwip-users digest..."

Today's Topics:

   1. Re: missing TX packets (Pomeroy, Marty)


---------- Forwarded message ----------
From: "Pomeroy, Marty" <address@hidden>
To: "Mailing list for lwIP users" <address@hidden>
Cc: 
Date: Tue, 7 Jan 2014 14:27:37 -0500
Subject: Re: [lwip-users] missing TX packets

 

* Don't run EMCCLK above 80MHz!  *

 

On the datasheet for the LPC178x/7x, page 84 and 85 shows that Tcy has a minimum of 12.5ns, which translates to a maximum EMC Clock of 80MHz.  We found out the hard way that it may work on most LPC1788s, but not on some!  Not recommended to run it above spec.

 

Our product using LPC1788 has LCD at max refresh rate, AND running the program itself out of DRAM, and no trouble with Ethernet.  Not sure where to look for issues...  make sure everything is using 32 bit transfers and DRAM is configured as a 32 bit interface...

 

 

---

From: lwip-users-bounces+martypomeroy=address@hidden [mailto:lwip-users-bounces+martypomeroy=address@hidden] On Behalf Of Lehel Benedek
Sent: Sunday, January 05, 2014 7:45 PM
To: address@hidden
Subject: Re: [lwip-users] missing TX packets

I managed to fix the problem by increasing the EMC clock rate from 60Mhz to 104Mhz and lowering the refresh rate of the LCD. The LCD controller was eating up all my bandwith to the external memory. Now both the webserver and the LCD are working nicely.

Thanks for your help.

 

_______________________________________________
lwip-users mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/lwip-users