Re: [Gumstix-users] LCD display - L_LCLK fault

[Craig H. <cr...@gu...>]

On Aug 7, 2006, at 3:21 AM, Leigh Gawne wrote:

> I have interfaced a 220x176 TFT to the LCD breakout on the GPSStix.  
> I am
> running the PXA on-board LCD controller in active mode, with a  
> resoultion of
> 220x176. Unfortunately, I am getting  no response from the LCD when
> attempting to write data to it. When probing the LCD controller  
> outputs, I
> see the pixel clock and the frame clock, which both look fine on a  
> scope
> trace. However, it appears the line clock is missing. As I  
> understand in
> active mode, the pixel clock, line clock and frame clock should all be
> running continuously independant of *new* data being written to the  
> display
> (as in passive mode).
>
> Before I put this issue down to a hardware fault and replace the  
> board, does
> anyone have any other suggestions as to what could cause the line  
> clock to
> be missing? I have been through the control registers and LCCR1  
> (control for
> the line sync) contains the following:

Check the GPIO settings on GPIO75 -- is it in the correct alt  
function mode?