MITSUBISHI MICROCOMPUTERS
M37274EFSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
(13) Scan Mode
M37274EFSP has the bi-scan mode for corresponding to HSYNC of
double speed frequency. In the bi-scan mode, the vertical start dis-
play position and the vertical size is two times as compared with the
normal scan mode. The scan mode is selected by bit 1 of the OSD
control register (refer to Figure 64).
Table 18. Setting for Scan Mode
Scan Mode
Bi-Scan
Normal Scan
Parameter
1
Bit 1 of OSD control register
0
Value of vertical position register ✕ 1H
1TC ✕ 1/2H
Value of vertical position register ✕ 2H
Vertical display start position
Vertical dot size
1TC ✕ 1H
1TC ✕ 2H
2TC ✕ 4H
3TC ✕ 6H
1TC ✕ 1H
2TC ✕ 2H
3TC ✕ 3H
Notes 1: Set values except “0016” and “0116” to the window H regis-
ter 1 when the window H register 2 is “0016.”
(14) Window Function
This function sets the top and bottom boundary of display limit on a
screen. The window function is valid only in the CC mode. The top
boundary is set by window H registers 1 and 2. The bottom bound-
ary is set by window L registers 1 and 2. This function is turned on
and off by bit 5 of the OSD control register (refer to Figure 64).
The window H registers 1 and 2 is shown in Figures 96 and 97, of
window L registers 1 and 2 is shown in Figures 98 and 99.
2: Set the register value fit for the following condition :
(WH1 + WH2) < (WL1 + WL2)
Top
boundary
of window
EXOSD mode
CC mode
A B C D E
F G H
I
J
CC mode
CC mode
K L M N O
Window
P Q R S T
U V W X Y
OSD mode
Bottom
boundary
of window
Screen
Fig. 95. Example of Window Function
95
RENESAS [ RENESAS TECHNOLOGY CORP ]
