| REGISTER |
PURPOSE |
COMMENT |
ACCESS |
BIT |
ADDRESS |
P1
|
Read Joypad Info
|
P1F_5
P1F_4
P1F_3
P1F_2
P1F_1
P1F_0 |
W
W
R
R
R
R |
5
4
3
2
1
0 |
FF00
|
| SB |
Serial Transfer Data |
|
R/W |
|
FF01 |
| SC |
Serial I/O Control |
|
R/W |
|
FF02 |
| DIV |
Timer Divider |
|
|
|
FF04 |
| TIMA |
Timer Counter |
|
|
|
FF05 |
| TMA |
Timer Modulo |
|
|
|
FF06 |
TAC
|
Timer Control
|
Timer Start/Stop
Timer Speed |
R/W
R/W |
2
0 - 1 |
FF07 |
| IF |
Interrupt Flag |
|
R/W |
|
FF0F |
NR10
|
Audio Sweep
|
Sweep time
Sweep increase/decrease
Sweep shift |
R/W
R/W
R/W |
4 - 6
3
0 - 2 |
FF10
|
NR11
|
Audio Channel #1
|
Wave pattern duty
Sound length data |
R/W
R/W |
6 - 7
0 - 5 |
FF11
|
NR12
|
Envelope Channel #1
|
Initial value of
envelope
Envelope Up/Down
Number of envelope sweep |
R/W
R/W
R/W |
4 - 7
3
0 - 2 |
FF12
|
| NR13 |
Sound Frequency #1 |
Frequency LSB |
W |
|
FF13 |
NR14
|
Sound Frequency #1
|
Initialise
Counter/Consecutive selection
Frequency significant 3 bits |
W
W
W |
7
6
0 - 2 |
FF14
|
NR21
|
Audio Channel #2
|
Wave pattern duty
Sound length data |
R/W
R/W |
6 - 7
0 - 5 |
FF16
|
NR22
|
Envelope Channel #2
|
Initial value of
envelope
Envelope Up/Down
Number of envelope sweep |
R/W
R/W
R/W |
4 - 7
3
0 - 2 |
FF17
|
| NR23 |
Sound Frequency #2 |
Frequency LSB |
W |
|
FF18 |
NR24
|
Sound Frequency #2
|
Initialise
Counter/Consecutive selection
Frequency significant 3 bits |
W
W
W |
7
6
0 - 2 |
FF19
|
| NR30 |
Audio Channel #3 |
Sound On/Off |
R/W |
7 |
FF1A |
| NR31 |
Sound Length #3 |
Sound Length |
R/W |
|
FF1B |
| NR32 |
Volume #3 |
Select output level |
R/W |
5 - 6 |
FF1C |
| NR33 |
Sound Frequency #3 |
Frequency LSB |
W |
|
FF1D |
NR34
|
Sound Frequency #3
|
Initialise
Counter/Consecutive selection
Frequency significant 3 bits |
W
W
W |
7
6
0 - 2 |
FF1E
|
| NR41 |
Sound Length #4 |
Sound Length |
R/W |
0 - 5 |
FF20 |
NR42
|
Envelope Channel #4
|
Initial value of
envelope
Envelope Up/Down
Number of envelope sweep |
R/W
R/W
R/W |
4 - 7
3
0 - 2 |
FF21
|
NR43
|
Audio Counter
|
Frequency of polynomial
counter
Polynomial counter's step
Dividing ratio of frequency |
R/W
R/W
R/W |
4 - 7
3
0 - 2 |
FF22
|
NR44
|
Audio Counter
|
Initialise audio
Counter/Consecutive selection |
R/W
R/W |
7
6 |
FF23
|
NR50
|
Channel Control
|
Vin SO2 On/Off
SO2 output volume
Vin SO1 On/Off
SO1 output volume |
R/W
R/W
R/W
R/W |
7
4 - 6
3
0 - 2 |
FF24
|
NR51
|
Sound Output
|
Output sound 4 to SO2
Output sound 3 to SO2
Output sound 2 to SO2
Output sound 1 to SO2
Output sound 4 to SO1
Output sound 3 to SO1
Output sound 2 to SO1
Output sound 1 to SO1 |
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W |
7
6
5
4
3
2
1
0 |
FF25
|
NR52
|
Sound On/Off
|
All Channels On/Off
Channel #4 On/Off
Channel #3 On/Off
Channel #2 On/Off
Channel #1 On/Off |
R/W
R/W
R/W
R/W
R/W |
7
3
2
1
0 |
FF26
|
| AUD3WAVERAM |
Wave Data |
Sound sample RAM (16
bytes) |
R/W |
|
FF30 - FF3F |
LCDC
|
LCD Control
|
LCD On/Off
Window Address
Window On/Off
Background Address
Object Size
Object On/Off
Background On/Off |
R/W
R/W
R/W
R/W
R/W
R/W
R/W |
7
6
5
3 - 4
2
1
0 |
FF40
|
STAT
|
LCD Status
|
LYCEQULY
Coincidence
Mode 10
Mode 01 (V-Blank)
Mode 00 (H-Blank)
Coincidence Flag
OAM/VRAM Lock |
R/W
R/W
R/W
R/W
R/W
R/W |
6
5
4
3
2
1 - 0 |
FF41
|
| SCY |
Scroll Screen Y |
Vertical Scroll |
R/W |
|
FF42 |
| SCX |
Scroll Screen X |
Horizontal Scroll |
R/W |
|
FF43 |
| LY |
LCDC Y-Coord |
|
R/W |
|
FF44 |
| LYC |
LY Compare |
|
R/W |
|
FF45 |
| DMA |
DMA Transfer |
|
R/W |
|
FF46 |
| BGP |
BG Palette Data |
|
R/W |
|
FF47 |
| OBP0 |
Object Palette 0 Data |
|
R/W |
|
FF48 |
| OBP1 |
Object Palette 1 Data |
|
R/W |
|
FF49 |
| WY |
Window Y Position |
|
R/W |
|
FF4A |
| WX |
Window X Position |
|
R/W |
|
FF4B |
| KEY1 |
CPU Speed Select |
GBC only |
R/W |
|
FF4D |
| VBK |
VRAM Bank Select |
GBC only |
R/W |
|
FF4F |
| HDMA1 |
HBL General DMA |
GBC only |
R/W |
|
FF51 |
| HDMA2 |
HBL General DMA |
GBC only |
R/W |
|
FF52 |
| HDMA3 |
HBL General DMA |
GBC only |
R/W |
|
FF53 |
| HDMA4 |
HBL General DMA |
GBC only |
R/W |
|
FF54 |
| HDMA5 |
HBL General DMA |
GBC only |
R/W |
|
FF55 |
| RP |
Infrared Comms |
GBC only |
R/W |
|
FF56 |
| BCPS |
BG Colour Index |
GBC only |
R/W |
|
FF68 |
| BCPD |
BG Colour Data |
GBC only |
R/W |
|
FF69 |
| OCPS |
Object Colour Index |
GBC only |
R/W |
|
FF6A |
| OCPD |
Object Colour Data |
GBC only |
R/W |
|
FF6B |
| SVBK |
RAM Bank Select |
GBC only |
R/W |
|
FF70 |
IE
|
Interrupt Enable
|
HILO Transition
Serial I/O Transfer Done
Timer Overflow
LCDC
VBL |
R/W
R/W
R/W
R/W
R/W |
4
3
2
1
0 |
FFFF
|
