cxa2025as Sony Electronics, cxa2025as Datasheet - Page 28

• Manufacturer Part Number: cxa2025as
• Description: Y/c/rgb/sync/deflection For Color Tv
• Manufacturer: Sony Electronics

1) 16:9 CRT full mode
This mode reproduces the full 480 lines on a 16:9 CRT. 4:3 images are reproduced by stretching the picture to
the left and right. Normal images are compressed vertically, but 16:9 images can be reproduced in their
original 16:9 aspect ratio with a video source which compresses (squeezes) 16:9 images to 4:3 images.
The register settings are the 16:9 CRT standard values.
2) 16:9 CRT normal mode
In this mode, 4:3 images are reproduced without modification. A black border appears at the left and right of
the picture. In this mode, the H deflection size must be compressed by 25% compared to full mode. The
CXA2025AS also has a register (H-SIZE) which controls the H size, but the control width is not sufficient for
25% compression. Therefore, external measures must be taken such as switching the H deflection coil, etc.
Full mode should be used when performing memory processing and attaching a black border to the video
signal.
H blanking of the image normally uses the flyback pulse input to AFCPIN (Pin 36). However, the blanking
width can be varied according to the control register setting when blanking is insufficient for the right and left
black borders.
The following three settings are added to the 16:9 CRT standard values for the register settings.
The H angle of deflection also decreases, causing it to differ from the PIN compensation amount during H size
full status. Therefore, in addition to the wide mode registers, PIN-COMP must also be readjusted only for this
mode.
3) 16:9 CRT zoom mode
In this mode, 4:3 images are reproduced by enlarging the picture without other modification. The top and
bottom of normal 4:3 images are lost, but almost the entire picture can be reproduced for vista size video
software, etc. which already has black borders at the top and bottom. The enlargement ratio can be controlled
by the V-ASPECT register, and enlarging the picture by 33% compared to full mode allows zooming to be
performed for 4:3 images without distortion. In this case, the number of scanning lines is reduced to 360 lines
compared to 480 lines for full mode. The zooming position can be shifted vertically by the V-SCROLL register.
V blanking of the image normally begins from V sync and continues for 2H after the AKB reference pulse, and
the top and bottom parts are also blanked during this mode.
Adjust the following two registers with respect to the 16:9 CRT standard values for the register settings.
4) 16:9 CRT subtitle-in mode
When Cinema Scope size images which have black borders at the top and bottom of the picture are merely
enlarged with the zoom mode in 3) above, subtitles present in the black borders may be lost. Therefore, this
mode is used to super-compress only the subtitle part and reproduce it on the display.
Add the LO-VLIN adjustment to the zoom mode settings for the register settings.
The LO-VLIN register causes only the linearity at the bottom of the picture to deteriorate. Therefore, UP-VLIN
should also be adjusted if the top and bottom of the picture are to be made symmetrical. Since the picture is
compressed vertically, the number of scanning lines exceeds 360 lines.
HBLKSW = 1
LEFT-BLK = Adjustment value
RIGHT-BLK = Adjustment value
V-ASPECT = 2FH
V-SCROLL = 1FH or user control
V-ASPECT = 2FH
V-SCROLL = 1FH or user control
LO-VLIN = Adjustment value
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CXA2025AS