YM2151 - register maps?

grommile

New Member
Nov 24, 2019
17
7
3
Northampton, UK
Since, of the planned sound chips for the CX16, the emulator only offers the YM2151 for now, can anyone point me to a downloadable register map (or, even better, register map + programming guide) for the YM2151?

My google-fu is failing me.
 

BruceMcF

Active Member
May 19, 2019
205
63
28
Since, of the planned sound chips for the CX16, the emulator only offers the YM2151 for now, can anyone point me to a downloadable register map (or, even better, register map + programming guide) for the YM2151?

My google-fu is failing me.
Well, the external register map is a pair of addresses, one to read/write the internal register address, and the other to read/write the currently addresses internal register ... but the 256 internally addressed registers are indeed hard to track down. The source referred to by the TEXELEC-S.AAYM card documentation (pdf) is the clearest one I can see in a quick search:

Yamaha FM-Sound Synthesizer Unit documentation Ver:1.0
 

jjbliss

New Member
Sep 26, 2019
1
3
3
If you're still looking for something, this can be a bit useful:

The page is a guide to programming the Sharp x68000, which uses the YM2151. Here is the important part, though on the page the color highlighting makes it a lot easier to figure out.

YM2151 Registers
The YM2151 is controlled by 255 registers, that are summarized below:
Address
7
6
5
4
3
2
1
0
Summary
Bit Meanings
$01
T​
T​
T​
T​
T​
T​
T​
T​
Test​
T=Test​
$08
-​
S​
S​
S​
S​
C​
C​
C​
Key On (Play Sound)​
C=Channel S=Slot (C2 � M2 � C1 � M1)​
$0F
E​
-​
-​
F​
F​
F​
F​
F​
Noise​
E=noise enable F=Frequency​
$10
C​
C​
C​
C​
C​
C​
C​
C​
CLKA1​
$11
-​
-​
-​
-​
-​
-​
C​
C​
CLKA2​
$12
C​
C​
C​
C​
C​
C​
C​
C​
CLKB​
$14
C​
-​
F​
F​
I​
I​
L​
L​
C=CSM F=F-Reset I=IRQEN L=LOAD​
$18
L​
L​
L​
L​
L​
L​
L​
L​
LFREQ​
$19
M​
M​
M​
M​
M​
M​
M​
M​
PMD/AMD​
$1B
D​
C​
-​
-​
-​
-​
W​
W​
D=Disk state C=CT (4mhz/8mhz) W=Waveform (0=Saw 1=Square,2=Tri, 3=Noise)​
$20-$27
L​
R​
F​
F​
F​
C​
C​
C​
Chn1-7�​
F=Feedback, C=Connection​
$28-$2F
-​
O​
O​
O​
N​
N​
N​
N​
Chn1-7� KeyCode​
O=Octive, N=Note​
$30-$37
F​
F​
F​
F​
F​
F​
-​
-​
Chn1-7� Key Fraction​
F=Fraction​
$38-$3F
-​
P​
P​
P​
-​
A​
A​
A​
Chn1-7� PMS / AMS​
P=PMS , A=AMS​
$40-$5F
-​
D​
D​
D​
M​
M​
M​
M​
Slot1-32. Decay/Mult​
D=Decay D1T, M=Mult​
$60-$7F
-​
V​
V​
V​
V​
V​
V​
V​
Slot1-32. Volume​
V=Volume (TL) (0=max)​
$80-$9F
K​
K​
-​
A​
A​
A​
A​
A​
Slot1-32. Keyscale / Attack​
K=Keycale, A=attack​
$A0-$BF
A​
-​
-​
D​
D​
D​
D​
D​
Slot1-32. AMS / Decay​
A=AMS-EN, D=Decay D1R​
$C0-$DF
T​
T​
-​
D​
D​
D​
D​
D​
Slot1-32. DeTune / Decay​
T=Detune DT2, D=Decay D2R​
$E0-$FF
D​
D​
D​
D​
R​
R​
R​
R​
Slot1-32. Decay / Release​
D=Decay D1L, R=Release Rate​