
VIII PERIPHERAL MODULES 6 (LCD): LCD CONTROLLER (LCDC)
VIII-1-28
EPSON
S1C33E07 TECHNICAL MANUAL
VIII.1.6.2 Setting the Display Start Address and Line Address Offset
Display start address
The display memory address from which to start display for the main window can be changed as desired using
the Main Window Display Start Address Register (0x301A70). The start address set in the Main Window Dis-
play Start Address Register (0x301A70) corresponds to the upper left edge of the LCD panel. Note that a word
boundary address (A[1:0] = 0b00) in IVRAM or the external SDRAM must be specified to this register.
Line address offset
The S1C33E07 LCDC manipulates display data in units of words. Therefore, the image width (number of pix-
els) must be a multiple of (32 bits
÷ bpp). The line address offset is the number of words corresponding to the
image width and it should be specified in the following cases:
1. When the Picture-in-Picture Plus function is used (when a sub-window is displayed)
2. When the LCD panel horizontal resolution is not a multiple of (32 bits
÷ bpp)
The line address offset is calculated as follows:
Main window line address offset = Main window width in pixels
× bpp / 32
Set this value to MWLADR[9:0] (D[9:0]/0x301A74).
MWLADR[9:0]: Main Window Line Address Offset Bits in the Main Window Line Address Offset Register
(D[9:0]/0x301A74)
(1) When the LCD panel horizontal resolution is a multiple of (32 bits
÷ bpp)
Example 1) LCD panel width = 320 pixels, 1-bpp mode
Main window line address offset = 320
× 1 / 32 = 10 [words]
Example 2) LCD panel width = 160 pixels, 8-bpp mode
Main window line address offset = 160
× 8 / 32 = 40 [words]
When using the Picture-in-Picture Plus function, set the calculated value to MWLADR[9:0] (D[9:0]/
0x301A74).
When the Picture-in-Picture Plus function is not used, it is not necessary to set MWLADR[9:0] (D[9:0]/
0x301A74). Leave it unaltered from 0 or set the calculated value to MWLADR[9:0] (D[9:0]/0x301A74) to
display normally. Be sure to avoid setting another value.
(2) When the LCD panel horizontal resolution is not a multiple of (32 bits
÷ bpp)
Example 3) LCD panel width = 240 pixels, 1-bpp mode
Main window line address offset = 240
× 1 / 32 = 7.5 [words] → 8 [words]
In this case, the calculated results have a decimal fraction. It must be rounded up.
MWLADR[9:0] (D[9:0]/0x301A74) must be set to 8.
Furthermore, the image area with 256 (8
× 32) pixels wide must be prepared in the display memory.
Image data should be left justified in the area. The 0.5 word data (16 pixels) at the end of each line will not
be displayed.
240 pixels
LCD panel
Display memory
A
A: Main window start address
B: Main window line address offset
Dummy data
Main window data
Main window
256 pixels
B (8 words)
Figure VIII.1.6.2.1 Data Layout in Image Area with Offset
When the LCD panel horizontal resolution is not a multiple of (32 bits
÷ bpp), a main window line address
offset must be set to MWLADR[9:0] (D[9:0]/0x301A74) regardless of whether the Picture-in-Picture Plus
function is used or not.