SDA5250 Datasheet, PDF (26/143 Pages) Siemens Semiconductor Group – TVTEXT 8-Bit Microcontroller

SDA 525x
Display Mode Register DMOD
Display Mode Register
Default after reset: XXXX0000B
(MSB)
–
–
–
DMOD
–
0
SFR-Address D6_H
(LSB)
0
0
DSDW
DSDW
Bit 1 to 3
if set, displaying Double Size and Double Width characters is
enabled
if cleared, control codes 0E_H and 0F_H have no effect
have always to be written with ‘0’
Bit 4 to 7
not implemented, to be written with ‘0’
Note: This register is not readable. Thus, do not use read-modify-write operations like
ANL, ORL to modify this register.
Display Feature Double Size and Double Width
Double Size and Double Width are selectable via serial attributes. The control codes are
‘0E’ for Double Width and ‘0F’ for Double Size. Now, there are 4 control codes available,
to modify the character size:
Control Name
Code
Effect
Side Effects
0C
Normal Size No stretching
any activated stretching off
0D
Double Height Vertical character stretching horizontal stretching off
0E
Double Width Horizontal character stretching vertical stretching off
0F
Double Size Horizontal and vertical
None
stretching
Since Double Width and Double Size control codes should not be interpreted by a pure
level 1 text-decoder, this size attributes have to be enabled by setting SFR-bit DSDW.
Double Width and Double Size characters are accomplished by skipping every second
character code after setting any of this following attributes where the remaining
displayable characters are stretched horizontally and thus conceating the character.
Although every second character is hidden, these codes will take effect if they are control
characters.
Semiconductor Group
26
1998-04-08