Page
4.4
Software Considerations
Attribute Codes
The
8 bits of data stored
in
the attribute
RAM
are used to control the
display of each character
in
the display. Six functions are available for
each
character and selected by the data
in
the attribute RAM. These func-
tions are shown in Table 4.3, along with the code that generates them.
In
order to blink the character, the blink enable bit
in
the control register
must
be
set as described earlier
in
this chapter.
Table 4.3.
Attribute
Codes
FUNCTION
ATrRIBUTE
DATA BITS CONTROL REGISTER
-::;-7---:6::----;:5,....-----.4--3;:;------;2::-----.--0;:;-- DATA BIT 3
Not displayed 0
o o o o
o
0 0 x
Intensity
background
Blink
x
x
x
x
x
x
x
x
x
x
x
x
x
x
o
Underline
x x x x x
o 0
x
Intensity
foreground
x
x
x
x
x x x x
Reverse
video
x x
o o 0 x
x = value does not affect attribute
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