Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 98

AGB Programming Manual
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Address Register
SOUND4
07Ch
CNT_H
SOUND4CNT_H [d15] Initialization Flag
A setting of 1 causes Sound 4 to be restarted.
SOUND4CNT_H [d14] Sound Length
Continuous sound output with 0; with 1, sound output only for the time
specified in the sound length data of NR41.
When sound output ends, the Sound 4 ON flag of NR52 is reset.
SOUND4CNT_H [d07 - 04] Polynomial Counter Shift Clock Frequency Selection
With n signifying the specified value, the shift clock frequency (shiftfreq) is
selected as shown in the following formula.
However, %1110 and %1111 are prohibited codes.
SOUND4CNT_H [d03] Polynomial Counter Step Number Selection
A value of 0 selects 15 steps; 1 selects 7 steps.
©1999 - 2001 Nintendo of America Inc.
NR44
Sound Length Flag
0: Continuous
1: Counter
Initialization
shiftfreq dividing ratio
NR43
Polynomial Counter Step
Number Selection
0: 15 steps
1: 7 steps
Polynomial Counter Shift
Clock Freq. Selection
1
frequency
( n ) 1
2
98
Sound
Attributes Initial Value
R/W 0000h
Dividing Ratio Freq.
Selection
D.C.N. AGB-06-0001-002B4