VGA 的同步旗子暗记是HSYNC 和VSYNC，它们在每行或每场数据的空闲产生高脉冲来达到同步的目的；而我们所利用的LCD，其旗子暗记同步办法不仅可以利用和VGA 类似的HSYNC 和VSYNC旗子暗记，也可以利用DE 旗子暗记来实现同步。当然了，无论是HSYNC/VSYNC 同步办法，还是DE 同步办法，对我们内部驱动时序的逻辑计数哀求都是差不多的。如图所示，DE 和HSYNC/VSYNC 摆在一起，它们的关系一览无余。DE 脉冲有效（高电平）期间，表示当前的RGB 数据是有效的，即显示在显示屏上的像素点色彩数据。
相对付HSYNC/VSYNC 驱动，DE 驱动办法反而更简洁一些，它的时序
波形如图所示。
为了便于实际的驱动计数器的时序产生， 我们还是须要和HSYNC/VSYNC 驱动办法一样，对行和列计数器的同步脉冲、后沿脉冲、显示脉冲、前沿脉冲做定义，它的脉冲计数表如下所示。把稳列的单位为“行”，而行的单位为“基定时钟周期数”，即33MHz 时钟脉冲数。
LCD 驱动时序参数表
ＧＰＩＯ扩展硬件连接
ＤＥ２开拓板上ＧＰＩＯ事理图
ＬＣＤ液晶屏事理图
对应管脚分配：
#clock & Reset
set_location_assignment PIN_N1 -to rst_n
set_location_assignment PIN_N2 -to clk
#LCD 800480
set_location_assignment PIN_U21 -to lcd_reset
set_location_assignment PIN_U20 -to lcd_pwm
set_location_assignment PIN_K26 -to lcd_de
set_location_assignment PIN_K25 -to lcd_dclk
set_location_assignment PIN_M22 -to lcd_vs
set_location_assignment PIN_M23 -to lcd_hs
set_location_assignment PIN_T21 -to lcd_red[7]
set_location_assignment PIN_T20 -to lcd_red[6]
set_location_assignment PIN_U26 -to lcd_red[5]
set_location_assignment PIN_U25 -to lcd_red[4]
set_location_assignment PIN_U23 -to lcd_red[3]
set_location_assignment PIN_U24 -to lcd_red[2]
set_location_assignment PIN_R19 -to lcd_red[1]
set_location_assignment PIN_T19 -to lcd_red[0]
set_location_assignment PIN_R25 -to lcd_green[7]
set_location_assignment PIN_R24 -to lcd_green[6]
set_location_assignment PIN_R20 -to lcd_green[5]
set_location_assignment PIN_T22 -to lcd_green[4]
set_location_assignment PIN_T23 -to lcd_green[3]
set_location_assignment PIN_T24 -to lcd_green[2]
set_location_assignment PIN_T25 -to lcd_green[1]
set_location_assignment PIN_T18 -to lcd_green[0]
set_location_assignment PIN_M19 -to lcd_blue[7]
set_location_assignment PIN_M20 -to lcd_blue[6]
set_location_assignment PIN_N20 -to lcd_blue[5]
set_location_assignment PIN_M21 -to lcd_blue[4]
set_location_assignment PIN_M24 -to lcd_blue[3]
set_location_assignment PIN_M25 -to lcd_blue[2]
set_location_assignment PIN_N24 -to lcd_blue[1]
set_location_assignment PIN_P24 -to lcd_blue[0]
终极显示效果图：
