Other Parts Discussed in Thread: TIDM-TM4C129XSDRAM
Tool/software: Starterware
I am reaching some timing limit for my LCD display. The TM4C129X LCD module is set to read from external SRAM through the EPI bus. The graphics libarary is configured to write to the same SRAM through the EPI bus.
Writing 1200 pixels seems to be my problem. Trying to writing this number of pixels results in an LCD interrupt, LCD_INT_UNDERFLOW. Writing 1,100 pixels give no problems. I am using 4BPP so writing a pixel is actually a read-modify-write because I only change 4 bits of a byte at a time.
Is there a way to prioritize reads from the EPI bus? Rendering the current frame is much more important than drawing the next frame. I would like a way to tell the writes to "chill" with the read FIFO is running low.
Other ideas are welcome.