4 Replies Latest reply on Mar 31, 2013 11:59 AM by user_134216630

    GLCD Controller speed

    user_134216630

      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

        • 1. Re: GLCD Controller speed
          user_14586677

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

             

          frequency ?

             

           

             

          Regards, Dana.

          • 2. Re: GLCD Controller speed
            user_134216630

            Dot clock is 9MHz. 

               

            Regards,

               

            Jan

            • 3. Re: GLCD Controller speed
              user_14586677

              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.

              • 4. Re: GLCD Controller speed
                user_134216630

                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