NXP Semiconductors LPC24XX UM10237 - Manual (Page 283)

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User manual Rev. 04 — 26 August 2009 283 of 792
NXP Semiconductors
UM10237
Chapter 12: LPC24XX LCD controller
The hardware cursor removes the requirement for this management by providing a
completely separate image buffer for the cursor, and superimposing the cursor image on
the LCD output stream at the current cursor (X,Y) coordinate.
To move the hardware cursor, the software driver supplies a new cursor coordinate. The
frame buffer requires no modification. This significantly reduces software overhead.
The cursor image is held in the LCD controller in an internal 256x32-bit buffer memory.
4.3 Types of LCD panels supported
The LCD controller supports the following types of LCD panel:
• Active matrix TFT panels with up to 24-bit bus interface.
• Single-panel monochrome STN panels (4-bit and 8-bit bus interface).
• Dual-panel monochrome STN panels (4-bit and 8-bit bus interface per panel).
• Single-panel color STN panels, 8-bit bus interface.
• Dual-panel color STN panels, 8-bit bus interface per panel.
4.4 TFT panels
TFT panels support one or more of the following color modes:
• 1 bpp, palettized, 2 colors selected from available colors.
• 2 bpp, palettized, 4 colors selected from available colors.
• 4 bpp, palettized, 16 colors selected from available colors.
• 8 bpp, palettized, 256 colors selected from available colors.
• 12 bpp, direct 4:4:4 RGB.
• 16 bpp, direct 5:5:5 RGB, with 1 bpp not normally used. This pixel is still output, and
can be used as a brightness bit to connect to the Least Significant Bit (LSB) of RGB
components of a 6:6:6 TFT panel.
• 16 bpp, direct 5:6:5 RGB.
• 24 bpp, direct 8:8:8 RGB, providing over 16 million colors.
Each 16-bit palette entry is composed of 5 bpp (RGB), plus a common intensity bit. This
provides better memory utilization and performance compared with a full 6 bpp structure.
The total number of colors supported can be doubled from 32K to 64K if the intensity bit is
used and applied to all three color components simultaneously.
Alternatively, the 16 signals can be used to drive a 5:6:5 panel with the extra bit only
applied to the green channel.
4.5 Color STN panels
Color STN panels support one or more of the following color modes:
• 1 bpp, palettized, 2 colors selected from 3375.
• 2 bpp, palettized, 4 colors selected from 3375.
• 4 bpp, palettized, 16 colors selected from 3375.
• 8 bpp, palettized, 256 colors selected from 3375.