N0ON	180020H	bit 0	NBG0
N1ON	180020H	bit 1	NBG1
N2ON	180020H	bit 2	NBG2
N3ON	180020H	bit 3	NBG3
R0ON	180020H	bit 4	for RBG0
R1ON	180020H	bit 5	for RBG1

xxON	Processing
0	Cannot display (does not access VRAM for display)
1	Can view

[Note] N0, N1, N2, N3, R0, or R1 is entered in the bit name xx.

∙ When an access command for a screen with this bit set to 0 is set in the VRAM cycle pattern register, the access command is ignored and VRAM access for displaying the screen is not performed.
* Do not set R1ON to 1 when R0ON is 0.
* When both R0ON and R1ON are set to 1, the normal scroll screen cannot be displayed. At this time, VRAM-B0 is fixed to RBG1 character pattern table RAM, and VRAM-B1 is fixed to RBG1 pattern name table RAM.
If a specific screen cannot be displayed due to register settings, set the bit of that screen to 0. For example, if both R0ON and R1ON are set to 1, set the N0ON, N1ON, N2ON, and N3ON bits to 0.
Please refer to “ 6.2 Rotation scroll screen display control ” for the rotation scroll screen.