Nintendo DMG-01 Manual - Page 41

FF11 NR 11

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Game BoyTM CPU Manual 2.13.1. I/O Registers 100: 31.3 ms (4/128Hz) 101: 39.1 ms (5/128Hz) 110: 46.9 ms (6/128Hz) 111: 54.7 ms (7/128Hz) The change of frequency (NR13,NR14) at each shift is calculated by the following formula where X(0) is initial freq & X(t1) is last freq: X(t) = X(t-1) +/- X(t-1)/2^n 10. FF11 (NR 11) Name - NR 11 Contents - Sound Mode 1 register, Sound length/Wave pattern duty (R/W) Only Bits 7-6 can be read. Bit 7-6 - Wave Pattern Duty Bit 5-0 - Sound length data (t1: 0-63) Wave Duty: (default: 10) 00: 12.5 01: 25 10: 50 11: 75 Sound Length = (64-t1)*(1/256) seconds by DP Page 41

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Game Boy
TM
CPU Manual
2.13.1. I/O Registers
100: 31.3 ms (4/128Hz)
101: 39.1 ms (5/128Hz)
110: 46.9 ms (6/128Hz)
111: 54.7 ms (7/128Hz)
The change of frequency (NR13,NR14) at
each shift is calculated by the following
formula where X(0) is initial freq & X(t-
1) is last freq:
X(t) = X(t-1) +/- X(t-1)/2^n
10.
FF11 (NR 11)
Name
- NR 11
Contents - Sound Mode 1 register, Sound length/Wave
pattern duty (R/W)
Only Bits 7-6 can be read.
Bit 7-6 - Wave Pattern Duty
Bit 5-0 - Sound length data (t1: 0-63)
Wave Duty: (default: 10)
00: 12.5% ( _--------_--------_-------- )
01: 25%
( __-------__-------__------- )
10: 50%
( ____-----____-----____----- )
11: 75%
( ______---______---______--- )
Sound Length = (64-t1)*(1/256) seconds
by DP
Page 41