8.9.2 Control registers details
8.9.2.1
DRWCONTROL - Geometry control register
This register controls the pixel enumeration and selection units, deciding which
pixels are part of the geometry.
Access
This register can be written in 32-bit units.
Address
<DrwE_Base> + 00
H
Index
0
Initial Value
0000 0000
H
. This register is initialized by any reset.
31
30
29
28
27
26
25
24
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
23
22
21
20
19
18
17
16
SPAN
STORE
SPAN
ABORT
UNION
CD
UNION
AB
UNION
56
UNION
34
UNION
12
BAND2
ENABLE
W
W
W
W
W
W
W
W
15
14
13
12
11
10
9
8
BAND1
ENABLE
LIM6
THRESH
OLD
LIM5
THRESH
OLD
LIM4
THRESH
OLD
LIM3
THRESH
OLD
LIM2
THRESH
OLD
LIM1
THRESH
OLD
QUAD3
ENABLE
W
W
W
W
W
W
W
W
7
6
5
4
3
2
1
0
QUAD2
ENABLE
QUAD1
ENABLE
LIM6
ENABLE
LIM5
ENABLE
LIM4
ENABLE
LIM3
ENABLE
LIM2
ENABLE
LIM1
ENABLE
W
W
W
W
W
W
W
W
Wrting to bits marked with "0" is ignored.
Bit
Bit name
Function
23
SPANSTORE
Nextline span start is always equal or left to current-line span start
0 disabled
1 enabled
22
SPANABORT
Shape is horizontally convex. only a single span per scanline
0 disabled
1 enabled
21
UNIONCD
Combine outputs C & D as union (output is final)
0 disabled
1 enabled
20
UNIONAB
Combine outputs A & B as union (output is called C)
0 disabled
Drawing Engine
Chapter 8
Preliminary User's Manual S19203EE1V3UM00
255
Summary of Contents for uPD72256
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