Module Overview
11-4
Figure 11–2.LCD Controller Block Diagram
16-Bit TFT
LCD controller
LCD.AC
LCD.HS
LCD.VS
LCD.PCLK
M
u
x
Palette
RAM
Gray-scaler
/serializer
Output
FIFO
Registers
Control
LCD.P
[15:0]
LCD panel
timings
generator
Frame buffer
MPU private
peripheral bus
LCD_CK
(from clock
and reset
management
block)
DMA request
LCD interrupt
(level 1 IRQ_31)
12/16 bpp
STN
Frame buffer data can be formatted for 2, 4, 8, 12, or 16-bit pixel sizes. A
16-entry x 12-bit palette supports the 2 and 4-bit pixel sizes, while a larger
256-entry x 12-bit palette supports the 8-bit pixel size. 12-bit and 16-bit pixel
sizes provide data that bypasses the palettes. The data is then processed
according to the desired type of display.
For passive monochrome panels, the 4-bit value indexed from the palette is
passed to the patented dither logic, where the desired brightness is created
using spatial and temporal dithering. The pixels are passed to the panel via a
4-wire interface, 4 pixels in parallel per pixel clock.
For passive color panels showing 8-bit color or lower, an entry from the palette
is transferred simultaneously into three parallel dither engines, one for each
of the red, green, and blue colors. These values are converted by the three
patented spatial and temporal dithering logic blocks to provide up to 256 colors
out of a possible 3375 colors (15 x 15 x 15). The pixels are passed to the panel
via an 8-wire interface, 2 2/3 pixels per clock.