GLCD Controller speed

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JaVa_282241
Level 2
Level 2
10 replies posted 5 questions asked 5 replies posted

Hi,

   

I tried to use GLCD controller component with 480x272 8bit col., touchscreen, PSOC5-60MHz.  It could be very usefull componet, but drawing to display  is quite slow. Yes, i could use virtual page, but it spend large amout of expensive SRAM(frame buffer).

   

I find out in GLCD controller datasheet that writing to frame buffer proceed on in blanking intervals.  Try everyone to write to frame buffer between two posedge dotclock using own component for the purpose acceleration? (controll registers+mux or verilog componet)? Eventually any idea to improve draving speed?

   

Thanks,

   

Jan

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ETRO_SSN583
Level 9
Level 9
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For the display you are using, and its color depth, what is the dot clock

   

frequency ?

   

 

   

Regards, Dana.

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JaVa_282241
Level 2
Level 2
10 replies posted 5 questions asked 5 replies posted

Dot clock is 9MHz. 

   

Regards,

   

Jan

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

I by no means am an expert in this area. That being said I would

   

tackle this by backing into it starting with a window of 111 nS to

   

do anything, eg. the dot clock. On top of that in the window,

   

a data transfer, there is decision overhead added to the

   

burden. So do the calculations for required BW then see if you

   

can match that up to PSOC.

   

 

   

Attached some material that may be of help.

   

 

   

In closing frame buffers in general have been a blessing to designers.

   

A lot of designs of yore with marginal timing and crippled image processing

   

fell into the buffer domain and were made into good designs. So much

   

for pontificating.

   

 

   

Regards, Dana.

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JaVa_282241
Level 2
Level 2
10 replies posted 5 questions asked 5 replies posted

Thanks for reply Dana.

   

You are right. I am using 55ns SRAM as frame buffer. It is too long write cycle to writing data to SRAM between two dotclock edge. Mayby in another desing i try to use 10ns SRAM.  It would then be possible to try writing to SRAM like above and GLCD controller component used only for generating TFT signals and screen refreshing.

   

Regards,

   

Jan

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