Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 35

AGB Programming Manual
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
Address Register
00Ch BG2CNT
00Eh BG3CNT
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
00
01
10
11
©1999 - 2001 Nintendo of America Inc.
Screen Base Block
0-31
Area Overflow Processing Flag
0: Transparent display
1: Wraparound display
Screen Size Screen Size
Text Screen
Screen Size Screen Data
256×256 2 Kbytes
512×256 4 Kbytes
256×512 4 Kbytes
512×512 8 Kbytes
0 0
Mosaic
0: Disable
1: Enable
Character Base Block
0-3
Color Mode
0: 16 colors x 16 palettes
1: 256 colors x 1 palette
Rotation/Scaling Screen
Screen Size
128×128
256×256
512×512
1024×1024
35
Rendering Functions
AttributesInitial Value
R/W 0000h
Priority Specification
00: 1st priority
01: 2nd priority
10: 3rd priority
11: 4th priority
Screen Data
256 Bytes
1 Kbyte
4 Kbytes
16 Kbytes
D.C.N. AGB-06-0001-002B4