Embedded Development Tools

[erdoganc]

hi,

i would like to use tft-vga controller in edk, but i have some trouble.

first of all, i used 1 plb in system and connected mplb and splb of tft to that bus. in this connection tft controller works. writes and draws objects. but the fps is too low, refreshing time is about 5-6 seconds. i searched out this situation in the forum and documents, then i found some solutions that are related to bus bandwidth.

1st: use one extra dcr bus and connect slave interface to that bus which is explained in tft controller pdf. but spartan 3e 1600 does not support dcr bus

2nd: add burst mode to the plb which is explained in the forum. this does not work

3rd: add one extra plb bus between mpmc pim-2 and mplb of tft, this does not work

i closed i-d cache or used interrupt nothing has changed.

i am strictly stucked 

any help is appreciated

[erdoganc]

a few more trial solved the situation.
improving the softcore performance and adding extra bus make fps rating fine

[pnarsbiwer]

Hi, im currently trying to do the exact same thing: to speed up the tft-vga controller on the spartan-3e 1600 dev board. Could you tell me the steps you did? Currently what i did was:

1. dump program code into block ram (works, but still not fast enough)

2. connect MPLB of vga controller directly to the MPMC (previously all was connected to the microblaze PLB), but this causes even the memory tests (in the SDK) to fail.

It would be great if you could attach ur project too!

Thanks!

[erdoganc]

hi pnars

i can advice you that use multi frame for tft, this prevevents viewer to realize the low fps rate

e.g

frame1: main display frame

frame2: workspace

first process frame2 and copy frame2 into frame1 via memcpy,

or you can use DMA instead of memcpy. this has a great impact on performance

[kwolfe81-bah]

Does anyone know why connecting an MPMC port directly to the TFT MPLB port causes the rest of the system to fail?  It's as if the TFT controller is hogging all of the DDR bandwidth and not allowing the Microblaze to function - but I could be wrong.  Time to start learning how to set priorities in the MPMC.

This issue has caused me many hours of frustration as I'm just starting out with this hardware and software set. It's taken me a while to isolate this as my problem as I have been unsure if any of my other actions were at fault.

[kwolfe81-bah]

Update: Solved the problem.  I simply needed to add a PLB to PLB bridge between the microblaze PLB bus and the VGA PLB bus.  Hope this helps someone in the future....