26 LCD CONTROLLER (LCDC)
26-32
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
Specify the sub-window start position using PIP_XSTART[9:0]/LCDC_SUBSP register for the X coordinate
and PIP_YSTART[9:0]/LCDC_SUBSP register for the Y coordinate. Use PIP_XEND[9:0]/LCDC_SUBEP reg-
ister for specifying the X coordinate of the end position and PIP_YEND[9:0]/LCDC_SUBEP register for the Y
coordinate.
The X coordinate should be specified with the number of data words converted from the number of pixels from
the LCD panel origin point according to the bpp mode. Therefore, it can be specified in (32 bits
÷
bpp) pixel
increments.
1-bpp mode:
1-word = 32-pixel units
2-bpp mode:
1-word = 16-pixel units
4-bpp mode:
1-word = 8-pixel units
8-bpp mode:
1-word = 4-pixel units
12-bpp mode: 3-word = 8-pixel units (because the value must be an integer)
16-bpp mode: 1-word = 2-pixel units
24-bpp mode: 3-word = 4-pixel units (because the value must be an integer)
For example, to specify the sub-window horizontal start position as 80 pixels in 8-bpp mode, set PIP_
XSTART[9:0] to 20.
The Y coordinate is specified with the number of lines from the LCD panel origin point in line units. For ex-
ample, to specify the sub-window vertical start position as 60 lines, set PIP_YSTART[9:0] to 60.
Sub-screen address offset for virtual screen
The virtual screen feature can also be used for the sub-window. Specify the screen address offset using SW_
OFS[11:0]/LCDC_SUBOFS register.
Sub-screen address offset = Virtual screen width in pixels
×
bpp / 32 [words]
See “Main screen address offset for virtual screen” in Section 26.6.2 for more information on the virtual screen
and the configurations.
Sub-window display control
The Picture-in-Picture Plus function is enabled and the sub-window is displayed by setting PIP_EN/LCDC_
SUBSP register to 1. This bit must be set after the sub-window configuration parameters are set up.
At initial reset, PIP_EN is set to 0 and sub-window is disabled for display.
Sub-window configuration example
The following shows an example to configure main and sub-windows.
[Conditions]
• LCD panel resolution:
320
×
240 pixels
• bpp mode:
4 bpp (16 shades of gray/16 colors)
• Memory used:
External SDRAM (Area 19, from 0x10000000)
• Virtual main screen size: 800
×
600 pixels, located at 0x10000000
• Virtual sub-screen size:
640
×
480 pixels, located at 0x10100000 (larger screen than the main screen,
such as 1024
×
768 pixels can also be configured.)
• Sub-window size:
160
×
120 pixels
• Sub-window start position: X = 80 pixels, Y = 60 pixels