User`s manual

115
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
MITSUBISHI MICROCOMPUTERS
Rev. 1.0
M37281MAH–XXXSP,M37281MFH–XXXSP
M37281MKH–XXXSP,M37281EKSP
8.11.17 Scan Mode
This microcomputer has the bi-scan mode for corresponding to HSYNC
of double speed frequency. In the bi-scan mode, the vertical start
display 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 1 (refer to Figure 8.11.3).
Scan Mode
Parameter
Bit 1 of OSD Control Register 1
Vertical Display Start Position
Vertical Dot Size
Table 8.11.9 Setting for Scan Mode
Normal Scan
0
Value of vertical position register ✕ 1H
1TC ✕ 1/2H
1TC ✕ 1H
2TC ✕ 2H
3TC ✕ 3H
Bi-Scan
1
Value of vertical position register ✕ 2H
1TC ✕ 1H
1TC ✕ 2H
2TC ✕ 4H
3TC ✕ 6H