Datasheet

AVR32416

32105-AVR32-07/08

Table 3-1. Frame buffer data ordering 24-bit resolution not packed

MSB LSB

31 – 24 23 – 16 15 – 8 7 - 0

Unused Blue Green

Red

The packed 24-bit resolution removes the unneeded empty 8-bit which results in a

smaller frame buffer. Table 3-2 shows how the data must be placed in the frame

buffer in order to be compliant with a packed 24-bit configuration. The second blue

component belongs to the next pixel.

Table 3-2. Frame buffer data ordering 24-bit resolution packed

MSB LSB

31 – 24 23 – 16 15 – 8 7 - 0

Blue Green Red

Blue

In a 16-bit resolution configuration a BGR-555.1 format is used by the LCD controller.

This means each color component uses 5-bits and the whole pixel gets one intensity

bit. Table 3-3 describes the needed data ordering in the frame buffer for a 16-bit

resolution configuration.

Table 3-3. Frame buffer data ordering 16-bit resolution

MSB LSB

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

I B4 B3 B2 B1 B0 G4 G3 G2 G1 G0 R4 R3 R2 R1 R0

If a graphics library does not support the frame buffer layout natively it has to swap

the colors accordingly. This will decrease the performance.

The formats RGB-888 and RGB-565 for instance can be supported by a special

hardware wiring and software configuration. The chapter 2.1.2 describes the needed

hardware wiring and 3.6.2.1 the needed software configuration for these examples.

3.6 Board setup code

Two things must be done to add the LCD controller and the LCD driver in the board

setup code. These are the registering of the LCD controller as a platform device and

the registering of the LCD driver as a platform driver.

3.6.1 Registering the LCD controller as platform device

Three structures must be edited and combined to form the information for the frame

buffer driver and the LCD controller driver. The LCD configuration of the STK1000

serves here as an example to explain the needed editing. The first structure specifies

the default mode (configuration) of the LCD controller.

static struct fb_videomode __initdata ltv350qv_modes[] = {

{

.name = "320x240 @ 75",

.refresh = 75,

.xres = 320,

.yres = 240,

.pixclock = KHZ2PICOS(6891),

.left_margin = 17,