NEC uPD72257, Preliminary User'S Manual

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Bit Bit name Function
8 BGR
Blue-Red swapped output
By setting BGR the display output signals of the blue VOnB[5:0] adn red VOnR[5:0]
channels are swapped.
0 RGB output
1 BGR output (VOnB[5:0] and VOnR[5:0] swapped)
5 bit 5
The default value "0" of this bit must be changed to "1" after reset and must not be altered
afterwards.
3 to 1 LCDBPP[2:0]
Colour format selection
011
B
8 bpp CLUT(8) mode
101
B
18 bpp RGB(666) true colour mode
110
B
16 bpp RGB(565) true colour mode
The colour format selection determines the colour format of the pixel data in the
framebuffer as well as the format of the display data output.
0 LCDEN
Video Output control enable
LCDEN = 1 enables the Video Output control signals VOnHSYNC, VOnVSYNC, VOnCLK,
VOnEN.
0 control and display data signals disabled (output low level)
1 control signals enabled (active)
LCDEN = 0 disables also the display data signals VOnR[5:0], VOnG[5:0], VOnB[5:0].
Note that LCDEN = 1 only enables the control, but not the data signals. Those have to
be additionally enabled by LCDPWR = 1.
Video Output Chapter 7
Preliminary User's Manual S19203EE1V3UM00
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