
VIII PERIPHERAL MODULES 6 (LCD): LCD CONTROLLER (LCDC)
S1C33E07 TECHNICAL MANUAL
EPSON
VIII-1-29
VIII
LCDC
The main window line address offset corresponds to one display line in the display memory. By adding/sub-
tracting this value or a multiple to/from the Main Window Display Start Address Register (0x301A70), the im-
age can be scrolled vertically.
VIII.1.6.3 Writing Display Data
The LCD controller may generate an interrupt at the beginning with the vertical non-display period after finishing
each frame refresh sequence. Furthermore, VNDPF (D7/0x301A04) is provided and is set to 1 if the display is in a
vertical non-display period.
VNDPF: Vertical Display Status Flag in the Status and Power Save Configuration Register (D7/0x301A04)
To eliminate screen flicker, display data, LUT data and the display buffer should be changed in a vertical non-
display period by using this interrupt or VNDPF (D7/0x301A04).
For more information on the LCDC interrupt, see Section VIII.1.7, “LCDC Interrupt and DMA.”
VIII.1.6.4 Inverting and Blanking the Display
The display can be blanked (the entire screen turned black or white) without rewriting the contents of the display
memory. Setting BLANK (D24/0x301A60) to 1 causes the FPDAT signal to go low or high, blanking the display.
Setting it to 0 turns the display back on. Whether the screen turns black or white is determined by SWINV (D25/
0x301A60) described below.
BLANK: Display Blank Enable Bit in the LCDC Display Mode Register (D24/0x301A60)
SWINV: Software Video Invert Bit in the LCDC Display Mode Register (D25/0x301A60)
Furthermore, the display can be inverted simply by manipulating a control bit. Setting SWINV (D25/0x301A60) to
1 inverts the display, and setting it to 0 returns the display to normal. (This function is effective only for STN panels
and it does not support HR-TFT panels.) This is accomplished by inverting the display data output from the look-up
tables, rather than by inverting the pixel data in the display memory.
The screen can be made to blink using these operations. Make sure switching takes place within the vertical non-
display period (VNDPF (D7/0x301A04) = 1).
VIII.1.6.5 Picture-in-Picture Plus
Picture-in-Picture Plus enables a sub-window to be displayed within the main window. The sub-window may be
positioned anywhere within the main window and is controlled through the sub-window control registers. The sub-
window retains the same color depth as the main window.
The following diagram shows the sub-window configuration parameters.
Main window
Sub-window
B
C
D
E
A
A: Panel's origin = Main window start address
B: Sub-window x start position
C: Sub-window y start position
D: Sub-window x end position
E: Sub-window y end position
Figure VIII.1.6.5.1 Sub-window Configuration Parameters
Note: When using the Picture-in-Picture Plus function, the main window line address offset must be set
to MWLADR[9:0] (D[9:0]/0x301A74). See Section VIII.1.6.2.