Sound Control Registers - Nintendo GAME BOY Programming Manual

Game Boy Programming Manual

2.5 Sound Control Registers

Name Address Bit 7
FF24
NR50
Output Level:
000: Minimum level (Maximum level 8)
:
:
111: Maximum level
V i n!SO1 ON/OFF (V i nSO2!ON/OFF)
Synthesizes audio input from Vin terminal with sounds 1-4 and ouputs the result.
0: No output
1: Output
Name Address
FF25
NR51
0: No Output
1: Output
Name Address Bit 7
NR52 FF26
6 5 4 3 2 1
Bit 7 6 5 4
6 5 4 3 2 1
0
R/W
SO1 Output Level(0-7)
Vin S01 On/Off
SO2 Output Level(0-7)
Vin
S02 On/Off
3 2 1 0
R/W Selects a Sound Output Terminal
Output Sound 1 to Terminal SO1
Output Sound 2 to Terminal SO1
Output Sound 3 to Terminal SO1
Output Sound 4 to Terminal SO1
Output Sound 1 to Terminal SO2
Output Sound 2 to Terminal SO2
Output Sound 3 to Terminal SO2
Output Sound 4 to Terminal SO2
0
R/W(Only the shaded portion
( ) can be read.)
Sound 1 On Flag
Sound 2 On Flag
Sound 3 On Flag
Sound 4 On Flag
Each flag is set during each sound output
in Counter Mode. The flag is reset after
the interval specified by the Length Data.
All Sound On/Off
0: Disable All Sound Circuits
1: Enable All Sound Circuits
90