EF9345 Datasheet, PDF (22/38 Pages) STMicroelectronics – HMOS2 SINGLE CHIP SEMI-GRAPHIC DISPLAY PROCESSOR

EF9345
USED DEFINED CHARACTER GENERATOR IN MEMORY : DOR REGISTER
With 40 char / row, the elementary window dimen-
sions on the screen are 10 slices x 8 pixels. Thus,
a character cell holds 10 bytes in memory and 4
character cells are packed in one 40-byte buffer
(Figure 21). However, 5 bytes of a low resolution
quadrichrome cell are enough to fill up to window.
In this case, 8 character cells can be packed in one
40-byte buffer.
Figure 21 : Packing UDS Cells in Memory
~~
~~
Character set base address
and
Character set number
Z block address
ONE
1K BYTE
BLOCK
0
39
0
8
9
4 CHARACTER CELLS
31
~~
~~
C6 C5 C4 C3 C2 C1 C0
Y
Slice number
(0 to 9)
54 32 10
NT
MEMORY
PIXELS
X
A CHARACTER SET LAYS IN ONE BLOCK
(up to 100 characters per set)
SLICE
NUMBER
(0 to 9)
NT
SLICE
NUMBER
(0 to 4)
NT
01234567
0
1
2
3
76543210
4
ONE SLICE
5
ONE BYTE
00000010
6
SLICES ARE SHIFTTED LSB FIRST
7
8
9
Character code C byte
(0 to 3 ; 32 to 127)
0
C6 C5 C4 C3 C2 C1 C0 k
0
1
TWO SLICES
1
ONE BYTE (repeated)
2
5
2
3
+
3
210
4
NT
4
NT*
543210
X
A SPECIAL CASE : LOW RESOLUTION QUADRICHROME CELL (R = 1)
(up to 200 characters per set)
NT* = 5k +NT
k = Subset index
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