Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 99

AGB Programming Manual
SOUND4CNT_H [d02 - 00] Dividing Ratio Frequency Selection
Selects a 14-step prescalar input clock to produce the shift clock for the
polynomial counter.
With f=4.194304 MHz, selection is as shown in the following table.
[Sound 4 Usage Note]
When a value is written to the envelope register, sound output becomes
unstable before the initialization flag is set. Therefore, set initialization flag
immediately after writing a value to the envelope register.
©1999 - 2001 Nintendo of America Inc.
Setting Dividing Ratio Frequency
000
001
010
011
100
101
110
111
99
3
fx1/2 x2
3
fx1/2 x1
3
fx1/2 x(1/2)
3
fx1/2 x(1/3)
3
fx1/2 x(1/4)
3
fx1/2 x(1/5)
3
fx1/2 x(1/6)
3
fx1/2 x(1/7)
Sound
D.C.N. AGB-06-0001-002B4