HD66781_1124769

•  Drive 262,144 TFT-color 240RGB x 320 dot graphics display in combination with HD66783 (a-Si
TFT panel) or HD667P21 (low-temperature poly-Si TFT panel)
•  Output signals to control HD66783, which incorporates a power supply integrated circuit and a gate
driver on a single chip.
•  Output signals to control a low-temperature poly-Si TFT panel with an incorporated gate driver
(combined use with HD667P21)
•  System interface
  High-speed bus interface with 8-/9-/16-/18-bit data bus
  Serial Peripheral Interface (SPI) 
•  Interfaces for moving picture display 
  RGB interface with 6-/16-/18-bit data bus (VSYNC, HSYNC, DOTCLK, ENABLE, PD17-0)
  VSYNC interface (System interface + VSYNC)
•  High-speed burst RAM write function
•  Compliant to single address mode for DMA transfer that controls data bus occupation ratio when transferring data from external SRAM
•  Window address function to write data to a rectangular area of RAM specified by the window address
  Interfaces for moving picture display, which write data to a rectangular RAM address area
  Reduce data transfer by transferring only the data for the moving picture display area 
  Simultaneous display of moving picture area and still picture area that displays the contents of internal RAM
  Resizing function (contraction rate: x1/2, x1/4 / magnification rate: x2, x4)
•  Various functions to control color display
  Simultaneous availability of 262,144 colors (settings are programmable)
  Partial OSD function
  -blending function (transmission rate: 0%, 25%, 50%, 75%, 100%)
•  Features for low-power architecture
  Interface I/O power supply       IOVcc = 1.7 ~ 3.3 V
                                                      Vcc1 = 1.7 ~ 3.3 V
  Logic regulator power supply           Vcc = 2.5 ~ 3.3 V
  Source driver liquid crystal driving voltage    DDVDH-GND = 4.0 ~ 5.9 V
  Power saving functions: standby mode, deep standby mode etc.
  Step-up circuits to generate liquid crystal drive voltage up to 12 times (HD66783 and HD667P21)
  Voltage followers for a liquid crystal drive power-supply, which fends off the direct current from leeder-resistors 
•  Cst structure only (Common Vcom formula)
•  224,640-byte (240 x (320+96) x 18bits) internal RAM
•  Incorporated LCD driver with 720 source outputs
•  Compliant to COG 
 

The HD66781 is a 720-channel source driver with graphics acceleration function, incorporating RAM
compliant to 262,144 TFT colors and 240RGB x 320 dot graphics.  In combination with the HD66783,
which incorporates a power-supply integrated circuit and a gate driver on a single chip, the HD66781 can drive an a-Si TFT panel of 240 RGB x 320 dots at maximum.  Also in combination with the HD667P21, which is a power-supply IC chip, the HD66781 can drive a low-temperature poly-Si TFT panel of 240 RGB x 320 dots at maximum with an incorporated gate driver.

The HD66781's high-speed RAM-write function through a high-speed interface of 8/9/16/18-bit bus enables efficient data transfer with high-speed burst RAM write function.  The HD66781 is compliant to DMA transfer single address mode to keep control on bus traffic occupation when a large volume of data is ransferred from external memory.  The HD66781 can also handle moving picture display through an RGB interface (VSYNC, HSYNC, DOTCLK, ENABLE, and PD 17 to 0).

The HD66781 incorporates RAM with the capacity of one QVGA-sized whole screen of 240 RGB x 320 x 18bits plus 96 raster-rows.  In addition to OSD and blending functions, which use this RAM area, the HD66781 also handles resizing function, which is compliant to data transfer for a large screen display.  These unctions make the HD66781 the best solution for the efficient and various ways of display.

The combined use of HD66781 with HD66783 or HD667P21 supports the function to reduce power consumption by a liquid crystal display system.  The HD66781's RAM can display 240 RGB x 320-dot color display (max.) with low voltage operation up to 1.7 V.  The HD66781 incorporates a voltage follower ircuit to generate liquid crystal driving voltages and an interfacing circuit that enables through HD66781 to make instruction settings to HD66783 and HD667P21.  In addition, the HD66781 supports power-saving modes such as standby mode and 8-color display mode, which allow precise power management by  software.  These features make this LSI the ideal solution for medium or small-sized portable battery-driven products such as digital cellular phones or small PDA with color displays, where long battery life  and board size are a major concern.