Samsung S3C2440A - Manual (Page 394)

LCD CONTROLLER S3C2440A RISC MICROPROCESSOR
15-26
LCD POWER ENABLE (STN/TFT)
The S3C2440A provides Power enable (PWREN) function. When PWREN is set to make PWREN signal enabled,
the output value of LCD_PWREN pin is controlled by ENVID. In other words, If LCD_PWREN pin is connected to
the power on/off control pin of the LCD panel, the power of LCD panel is controlled by the setting of ENVID
automatically.
The S3C2440A also supports INVPWREN bit to invert polarity of the PWREN signal.
This function is available only when LCD panel has its own power on/off control port and when port is connected to
LCD_PWREN pin.
VSYNC
HSYNC
VDEN
LCD_PWREN
1 FRAME
ENVID
LCD Panel On
TFT LCD
VLINE
VFRAME
STN LCD
LCD_PWREN
LCD Panel On
ENVID
Figure 15-8. Example of PWREN function (PWREN=1, INVPWREN=0)