Functional Overview
1. Reduction options
Vertical: Selectable 1/2, 1/3 and 1/4 reduction vertical filter coefficients.
Horizontal: (1/1) to 2/3 to (1/2) to 1/3 to (1/4) to 1/6. Intermediate values are implemented using the aspect
correction function.
2. Number of sub-screens
With 1 Mb of memory: 1 to 4 or (8). * Values in parentheses are for SPLIT mode, where the image quality is
reduced.
With 256 kb of memory: 1 or (2).
3. Static images
With 1 Mb of memory: Frame static image (supported with 2 or fewer screens) or field static images
With 256 kb of memory: Field static image
4. Display position
Screen A: Fixed positions in the four corners
Screen B: Free positioning (Specified by 8 bits in each of the vertical and horizontal directions.)
5. Frame
On/off selectable
Two types that differ by insertion method
— Pin frame: The frame position is specified by a high level pin output. (application frame insertion)
— D/A frame: A 50% white or arbitrary color overlapped on the Y, R-Y, and B-Y video signals.
6. Wipe
Twelve types
7. Blanking size
The vertical and horizontal directions can be specified independently (6 bits each)
Sixteen forms can be specified.
8. Blue background
The sub-screen can be set to all blue or all black.
9. Memory clear
Sets the data written to video memory to a fixed value corresponding to a 25% white color.
10. Wide-screen TV support
Aspect correction function
Subtitle shifting
The subtitle area can be trimmed and displayed as a sub-screen.
The vertical reduction ratio can be set independently to 1/4, 1/3, or 1/2. The horizontal reduction can be set to
values up to 1/1 using mode 2E.
11. Support for NTSC, PAL, and multi-mode (NTSC-PAL) products
12. External control functions using an I2C interface (LC74401E only)
Six 8-bit D/A converter circuits built-in (PWM)
Four general-purpose ports built-in
13. Setting adjustments
Fine adjustment of various settings, including sub-screen position displacement and color shift is supported.
No. 4872-6/19
LC74401E, 74402, 74402E