How to increase SPI display (ili9341) draw speed?

[JBond.1]

How to fill the screen with one color without seeing the draw pattern from top to bottom?

All I want is to make screen instantly change color. I understand that drawing bitmap might be slow, but I want just one color.

Is there a way to reduce display colors or something?

My STM32F091RC SPI is set to 8bit 36MHz with 18Mbps (as I understand 18Mbps is the max value).

SPI Display (ili9341) 240x320 TFT, but I need only few colors.

[waclawek.jan]

There's probably no magic way to speed this up, as SPI writes are 16- or 18-bits (the latter requires 24-bit SPI transfer per pixel, so I assume you already use the former), see 3-line Serial Interface chapter in the ILI9341 DS. So that's 320*240*16bpp/18Mbps=cca70ms, which is not that bad, but definitively visible, as it spans two or three display frames.

ILI9341 does not have any acceleration (e.g. bitblt machine) nor color lookup mode.

So, even if you don't want to hear it, the only way to achive higher speed is to use parallel interface.

JW