Hi, maybe it is too late but you should also check this site http://www.lpcware.com/content/nxpfile/lcd-bus-bandwidth-calculator-lpc177x8x to compute the bandwidth for your LCD controller.
Martin On Thu, Jan 9, 2014 at 2:50 AM, Lehel Benedek <[email protected]> wrote: > 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, <[email protected]> wrote: >> >> Send lwip-users mailing list submissions to >> [email protected] >> >> 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 >> [email protected] >> >> You can reach the person managing the list at >> [email protected] >> >> 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" <[email protected]> >> To: "Mailing list for lwIP users" <[email protected]> >> 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: [email protected] >> [mailto:[email protected]] On Behalf Of >> Lehel Benedek >> Sent: Sunday, January 05, 2014 7:45 PM >> To: [email protected] >> 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 >> [email protected] >> https://lists.nongnu.org/mailman/listinfo/lwip-users > > > > _______________________________________________ > lwip-users mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/lwip-users
