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4.5 Character control register

The character control register selects the cell format and bitmap format, specifies the number of character (bitmap) colors, and specifies the character pattern or bitmap size. This is a write-only 16-bit register located at addresses 180028H to 18002AH. The value is cleared to 0 after power-on or reset, so be sure to set it.

Character color number bit : Character color number bit

(N0CHCN2 to N0CHCN0, N1CHCN1, N1CHCN0, N2CHCN, N3CHCN, R0CHCN2 to R0CHCN0)
Specify the number of character colors for each screen. When displaying in bitmap format, specify the number of bitmap colors. 

 N0CHCN2 to N0CHCN0 
 180028H 
 bits 6-4 
 for NBG0 (or RBG1) 
 N1CHCN1, N1CHCN0 
 180028H 
 bits 13, 12 
 NBG1 (or EXBG) 
 N2CHCN 
 18002AH 
 bit 1 
 NBG2 
 N3CHCN 
 18002AH 
 bit 5 
 NBG3 
 R0CHCN2 to R0CHCN0 
 18002AH 
 bits 14 to 12 
 for RBG0 

 16 colors  
 256 colors  
 2048 colors  
 32768 colors  
 16.77 million colors  
 Setting prohibited (Do not set)  
 Setting prohibited (Do not set)  
 Setting prohibited (Do not set) 

N0CHCN2
N0CHCN1
 
 N0CHCN0 
 TV screen mode 
 Color format 
 Normal 
 High Resolution 
 Dedicated 
 Monitor 
0
0
0
 
 16 colors 
 16 colors 
 pallet format 
0
0
1
 
 256 colors 
 256 colors 
 pallet format 
0
1
0
 
 2048 colors 
 2048 colors 
 pallet format 
0
1
1
 
 32768 colors 
 32768 colors 
 RGB format 
1
0
0
 
 Setting prohibited 
 Setting prohibited 
 RGB format 
1
0
1
1
1
0
1
1
1
[Note] When used as RBG1, it cannot be displayed in the dedicated monitor mode.

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