10-03-2015 03:08 AM
01-23-2016 07:26 PM
I used AXI TFT controller v2.0 to use TFT LCD (800x480 24bit color) with HP port.
When AXI TFT controller used with linux driver (xilinxfb.c), framebuffer may be not aligned correctly.
According to LogiCORE IP Product Guide (PG095-axi-tft.pdf), address register(AR) uses only upper 11bit among 32bit address.
During allocation of framebuffer on DDR memory, lower 21 bit should be all zero.
But linux driver (xilinxfb.c) does not check whether lower 21 bit of framebuffer physical address is all zero or not.
If 21 bit of framebuffer physical address is not zero, TFT screen can be flicker.
Please refer to line number 294-301 of xilinxfb.c at github (JunghoYoo/xilinx-zynq-zc702-linuxapplication/tree/master/tft)