Nintendo 1504166 Programming Manual - Page 94

SOUND3CNT_H [d15] Forced 3/4 Output Level Specification Flag

Page 94 highlights

AGB Programming Manual Sound Address Register 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 Attributes Initial Value 072h SOUND3 CNT_H NR32 NR31 R/W 0000h Output Level Selection Forced 3/4 Output Level Spec. Flag Sound Length 0-255 SOUND3CNT_H [d15] Forced 3/4 Output Level Specification Flag With 0 specified, the output level specified in NR32 [d14-13] is used. A setting of 1 forces a 3/4 output level regardless of the setting in NR32 [d14-13]. SOUND3CNT_H [d14 - 13] Output Level Selection The Sound 3 output-level selections are as shown in the following table. Setting 00 01 10 11 Output Level Mute Outputs the waveform RAM data unmodified. Outputs the waveform RAM data with the contents right-shifted 1 bit (1/2). Outputs the waveform RAM data with the contents right-shifted 2 bits (1/4). SOUND3CNT_H [d07 - 00] Sound Length The sound length, time, is determined by the following formula, with st signifying the sound-length setting. time = (256 − st ) × 1 (sec) 256 Address Register 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 Attributes Initial Value 074h SOUND3 NR34 NR33 R/W 0000h CNT_X Sound Length Flag 0: Continuous 1: Counter Initializaton Flag Frequency Data SOUND3CNT_X [d15] Initialization Flag When SOUND3CNT_L [d07] is 1, a setting of 1 in this bit causes Sound 3 to restart. ©1999 - 2001 Nintendo of America Inc. 94 D.C.N. AGB-06-0001-002B4

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AGB Programming Manual
Sound
©1999 - 2001 Nintendo of America Inc.
94
D.C.N. AGB-06-0001-002B4
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
SOUND3
CNT_H
072h
0000h
R/W
Address
Register
Attributes
Initial
Value
NR31
NR32
Sound Length
0-255
Output Level Selection
Forced 3/4 Output Level Spec. Flag
SOUND3CNT_H [d15] Forced 3/4 Output Level Specification Flag
With 0 specified, the output level specified in NR32 [d14-13] is used.
A setting of 1 forces a 3/4 output level regardless of the setting in NR32
[d14-13].
SOUND3CNT_H [d14 - 13] Output Level Selection
The Sound 3 output-level selections are as shown in the following table.
Setting
Output Level
00
Mute
01
Outputs the waveform RAM data unmodified.
10
Outputs the waveform RAM data with the contents right-shifted
1 bit (1/2).
11
Outputs the waveform RAM data with the contents right-shifted
2 bits (1/4).
SOUND3CNT_H [d07 - 00] Sound Length
The sound length, time, is determined by the following formula, with st signifying
the sound-length setting.
time
st
=
-
×
(
)
(sec)
256
1
256
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
SOUND3
CNT_X
074h
0000h
R/W
Address
Register
Attributes
Initial
Value
NR33
NR34
Frequency Data
Sound Length Flag
0: Continuous
1: Counter
Initializaton Flag
SOUND3CNT_X [d15] Initialization Flag
When SOUND3CNT_L [d07] is 1, a setting of 1 in this bit causes Sound 3
to restart.