27 GRAPHICS ENGINE (GE)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
27-39
CIRCLE Command (Circle Drawing)
27.5.11
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
CMD
0x1b
0xffff
ARG1
Effect Setting
Color
1/
8
P
os
iti
on
S
el
ec
t
C
lip
E
na
bl
e
Tr
an
sp
ar
en
t E
na
bl
e
P
al
et
te
S
el
ec
t
S
yn
c
E
na
bl
e
W
rit
e
E
ffe
ct
S
et
tin
g
ARG2
reserved
Line Width
reserved
Radius
ARG3
Y Coordinate
X Coordinate
The CIRCLE command draws the circumference of a circle specified with the center coordinates, radius, and a line
color. The line width can be specified in number of pixels. Furthermore, this command allows selection of the arcs
to be drawn from the eight segments split by 45°.
Argument 1 (Drawing effects and color)
D[31:24] 1/8 Position Select[7:0] Bits
Selects one or more arcs to be drawn from eight locations split by 45°. Set the 1/8 Position Select[7:0]
bits corresponding to the arcs to be drawn to 1 and execute the command. To draw a complete circle, set
all the 1/8 Position Select[7:0] bits to 1.
b0 (0x1)
0x1
0x3
0x2
0xf
0x4
0x3f
0x8
0x11
0x10
0x33
0x20
0x55
0x40
0x6f
0x80
0xff
b3 (0x8)
b7 (0x80)
b4 (0x10)
b1 (0x2)
b2 (0x4)
b6 (0x40)
b5 (0x20)
1/8 Position Select[7:0]
Examples:
b7 b6 b5 b4 b3 b2 b1 b0
5.11.1 Arc Selections
Figure 27.
Note: When two or more arcs are drawn with separate commands, the pixels at the boundary are
overwritten. This must be taken into consideration when using a writing effect, XOR in particular.
If arcs are drawn in the same color, the XOR writing effect clears the overlaid boundary pixels.
D23
Clip Enable Bit
Enables or disables the clipping function. (See Section 27.3.5.)
1: Clipping enabled
0: Clipping disabled
D22
Transparent Enable Bit
Enables or disables transparency. (See Section 27.3.5.)
1: Transparency enabled
0: Transparency disabled
D[21:20] Palette Select[1:0] Bits
Selects the palette to be used when converting colors with a palette. (See Section 27.3.5.)
5.11.1 Palette Selection
Table 27.
Palette Select[1:0] bits
Palette
0x3
Palette 3
0x2
Palette 2
0x1
Palette 1
0x0
Not used
D19
Sync Enable Bit
Enables or disables the LCDC synchronization function. (See Section 27.3.5.)
1: Enabled (Synchronized)
0: Disabled (Not synchronized)