EF9345 Datasheet, PDF (24/38 Pages) STMicroelectronics – HMOS2 SINGLE CHIP SEMI-GRAPHIC DISPLAY PROCESSOR

EF9345
Figure 23 : Accessing a Character Slice in Memory Using OCT Command with Auxiliary Pointer
R1 SLICE
R2
R3
Y
R4
Z₂ C6 C5 C4 C3 C2
R5 Z₀ Z₁
X
NT
C1 C0
R6
Z₃
R7
On-Chip Character Generator
- G₀ set is common to 40 and 80 char./row modes
(Figure 24 and Figure 34).
- G₁₀ is the standard mosaïc set for videotex (Fig-
ure 25).
- G11, G20 and G21 cannot be reached from the
16-bit short fixed codes (Figure 26 and Figure 27).
Displaying the Attributes
1. For normal operation, a double height and/or
double width character must be repeated in
memory in two successive Y and/or X
positions. The user may otherwise freely mix
any character size.
2. The attributes are logically processed in the
following order :
- Underline or underline cursor : foreground
forced on the last slice (NT = 9).
- Flash : background periodically forced on the
whole window (0.5Hz). The phase depends on
the negative attribute.
- Conceal : background forced permanently on
the whole window. A concealed character
neither blinks nor is underlined.
- Negative : exchange the background and
foreground color values when set.
- Coloring.
- Complemented cursor mode.
- Insert : black color forced when required.
3. Basic pixel shift frequency : f_CLK x 2/3 = 8MHz.
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