CXA2050S
Examples of various modes are listed below. These modes are described using 570 (NTSC: 480) lines as the
essential number of display scanning lines. Wide mode setting register data is also listed, but settings may
differ slightly due to IC variation. The standard setting data differs for 16:9 CRTs and 4:3 CRTs.
Register
16:9 CRT
4:3 CRT
V-ASPECT
V-SCROLL
ZOOMSW
UP-VLIN
LO-VLIN
JMPSW
0h
1Fh
1
0h
0h
0
2Fh
1Fh
0
0h
0h
0
HSIZESW
HBLKSW
LEFT-BLK
RIGHT-BLK
0
1
7h
7h
0
1
7
7h
1) 16:9 CRT full mode
This mode reproduces the full 570 (NTSC: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
CXA2050S permits compression with a register (HSIZESW) that compresses the H size by 25%. Because
excessive current flows to the horizontal deflection coil in this case, adequate consideration must be given to
the allowable power dissipation, etc., of the horizontal deflection coil in the design of the set. In addition, this
concern can also be addressed through measures taken external to the IC, such as by switching the horizontal
deflection coil. Full mode should be used when using memory processing to add a black border to the video
signal.
H blanking of the image normally uses the flyback pulse input to AFCPIN (Pin 44). 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.
HBLKSW = 1
LEFT-BLK = Adjustment value
RIGHT-BLK = Adjustment value
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 430 lines
compared to 570 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.
V-ASPECT = 2Fh
V-SCROLL = 1Fh or user control
– 37 –
SONY [ SONY CORPORATION ]
