AGB Programming Manual
Rendering Functions
©1999 - 2001 Nintendo of America Inc.
35
D.C.N. AGB-06-0001-002B4
2) Text BG and Rotation/Scaling BG Screen Control (BG2 and BG3)
Whether the screen is a text screen or a scaling/rotation screen varies
with the BG mode.
15
14 13
12
11 10
09
08 07
06
05 04
03
02 01
00
BG2CNT
BG3CNT
00Ch
00Eh
0000h
R/W
Address
Register
AttributesInitial Value
Priority Specification
00: 1st priority
01: 2nd priority
10: 3rd priority
11: 4th priority
Character Base Block
0-3
0
0
Screen Size
Screen Size
Mosaic
0: Disable
1: Enable
Color Mode
0: 16 colors x 16 palettes
1: 256 colors x 1 palette
Screen Base Block
0-31
Area Overflow Processing Flag
0: Transparent display
1: Wraparound display
BG*CNT [d15-14] Screen Size
Allows the screen size for the BG as a whole to be specified.
When a value other than the maximum is specified, the remaining VRAM
area can be used as a character data area.
Refer to the table below and the VRAM Memory Map figure above.
Screen Size
Setting
Text Screen
Rotation/Scaling Screen
Screen Size
Screen Data
Screen Size
Screen Data
00
256
×
256
2 Kbytes
128
×
128
256 Bytes
01
512
×
256
4 Kbytes
256
×
256
1 Kbyte
10
256
×
512
4 Kbytes
512
×
512
4 Kbytes
11
512
×
512
8 Kbytes
1024
×
1024
16 Kbytes