Nintendo 1504166 Programming Manual - Page 38

See VRAM Address Mapping of BG Data., priority is BG0, BG1, BG2, and BG3.

Page 38 highlights

AGB Programming Manual Rendering Functions BG2CNT,BG3CNT [d13] Area Overflow Processing When the display screen overflows the boundaries of the virtual screen due to a rotation/scaling operation, this bit can be used to choose whether the area of the screen into which the overflow occurs is displayed as transparent or wraps around the display screen. For information on scaling, see "6.1.7 BG Rotation and Scaling Features". BG*CNT [d12-08] Screen Base Block Specification Specifies the starting block in VRAM where screen data are stored. (32 steps: 0-31; 2-Kbyte increments). See section 6.1.3, VRAM Address Mapping of BG Data. BG*CNT [d07] Color Mode Specifies whether to reference BG character data in 16 color x 16 palette format or 256 color x 1 palette format. BG*CNT [d06] Mosaic Turns mosaic processing for BG on and off. BG*CNT [d03-02] Character Base Block Specification Specifies the starting block in VRAM where the character data to be displayed in the BG is stored. (4 steps: 0-3; 16-Kbyte increments) See section 6.1.3, VRAM Address Mapping of BG Data. BG*CNT [d01-00] Priority Among BGs With the default value (same priority value specified for all), the order of priority is BG0, BG1, BG2, and BG3. However, this order can be changed to any desired. Values of 0 (highest priority) to 3 can be specified. When the BG priority has been changed, care should be taken in specifying the pixels used for color special effects. ©1999 - 2001 Nintendo of America Inc. 38 D.C.N. AGB-06-0001-002B4

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AGB Programming Manual
Rendering Functions
©1999 - 2001 Nintendo of America Inc.
38
D.C.N. AGB-06-0001-002B4
BG2CNT,BG3CNT [d13]
Area Overflow Processing
When the display screen overflows the boundaries of the virtual screen
due to a rotation/scaling operation, this bit can be used to choose whether
the area of the screen into which the overflow occurs is displayed as
transparent or wraps around the display screen.
For information on scaling, see “6.1.7 BG Rotation and Scaling Features”.
BG*CNT [d12-08]
Screen Base Block Specification
Specifies the starting block in VRAM where screen data are stored.
(32 steps:
0-31; 2-Kbyte increments).
See section 6.1.3, VRAM Address Mapping of BG Data.
BG*CNT [d07]
Color Mode
Specifies whether to reference BG character data in 16 color x 16 palette
format or 256 color x 1 palette format.
BG*CNT [d06]
Mosaic
Turns mosaic processing for BG on and off.
BG*CNT [d03-02]
Character Base Block Specification
Specifies the starting block in VRAM where the character data to be
displayed in the BG is stored.
(4 steps:
0-3; 16-Kbyte increments)
See section 6.1.3, VRAM Address Mapping of BG Data.
BG*CNT [d01-00]
Priority Among BGs
With the default value (same priority value specified for all), the order of
priority is BG0, BG1, BG2, and BG3.
However, this order can be changed
to any desired.
Values of 0 (highest priority) to 3 can be specified.
When the BG priority has been changed, care should be taken in
specifying the pixels used for color special effects.