Two kinds of color expansion are supported in logiBITBLT.
The first is standard color expansion technique for color font creation and overlay creation. A monochromatic bitmap is expanded with background color and foreground color. Background color is set in background color register (BG_COL_REG), while foreground color is set in foreground color register (FG_COL_REG). The color in registers is set according to the destination bitmap color format. Color format is set in control 1 register (CTRL1_REG). Supported color formats are: RGB8, RGB16, RGB24, ARGB8, ARGB16 and ARGB24. Each monocromatic bitmap pixel is tranferred to the destination bitmap as a color pixel. The monochromatic pixel value determines among destination pixel foreground or background color. This option is included when generic parameter C_USE_EXPAND is set prior to implementation.
The second is anti-aliased 8-bit font expansion technique used to generate anti-aliased fonts. Fonts are stored in memory in 8-bit per pixel format (8 bpp). Each 8-bit value is expanded to corresponding 32-bit value (ARGB) stored in AA_FONT_COLOR_RAM register set located inside logiBITBLT register module. 8-bit value actually represents address (pointer) to anti-aliased font color RAM (AA_FONT_COLOR_RAM) and output is expanded 32-bit color value (with alpha channel). Anti-aliased effect is produced with properly selected alpha values stored in AA font color RAM. Value inside RAM is given in ARGB format (ARGB6565 or ARGB8888). AA font expansion cannot be used when ARGB3332 color format is selected. This option is included when generic parameter C_USE_AA_FONT_EXPAND is set prior to implementation.