uclinux on a 800x600 TFT

Jan 28, 2004 1 Replies

Hello



When I run my programs, there are horizontal lines of garbage on the screen.



This is my system configuration: Motorola MC5372C3 board with the ColdFire processor running at 66MHz A graphical board with the Epson s1d13806 graphic controller Unipac 800*600 TFT touch panel uClinux 2.4 with a framebuffer driver for the s1d13806



The s1d13806 clocks I am using just now (I have tested several combinations) are: BUSCLK = 66MHz MCLK = CLK1 = 40MHz LCDCLK = CLK1 = 40MHz



The s1d13806 technical information talks about screen corruption but only in stress conditions (affecting internal bandwidth) greater than mine. Even so, changing the fifo threshold registers and the SDRAM Control timing registers of the s1d13806 we got only a few lines but they are still there. If we write only on the non vertical display, the image are always clean, but the system gets too slow.



I am puzzled nobody gets a problem like this (at last i found no references on the net), and I see several boards on the net saiyng they work at such speeds. So, I thinkl I must be missing something trying to get the s1d13806 to work. But I can not think of anything more to try.



Any idea will be welcome.



Thanks, nafiton



Hello

Epson asks me to raise the power supply 200mv. We was at 3.29 and raise it to 3.46. The corruption get worst. Since the supply affected so much to the chip, we trid with another source of power and ... the screen went clean at whatever power supply voltage (into the permited range).

The problenm seems to be at the start. The board supply gets to the

3.28V very fast: 1ms. The external source goes very slowly: 35 ms.

There is something at the start that affects the s1d13806 behaviour. And to do a system reset does not resolve the problem.

Any idea? nafiton

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