9.0 Registers
A d d r e s s e s
C S 0
C S 1
D A 2
N
N
x
N
A
0
N
A
1
N
A
1
N
A
1
A
N
0
A
N
0
A
N
0
A
N
0
A
N
0
A
N
1
A
N
1
A
N
1
A
N
1
A
N
1
A
N
1
A
N
1
A
A
x
L o g i c c o n v e n t i o n s :
Figure 37. Register Set
Communication to or from the device is through an I/O Register that routes the input or output data to or
from registers addressed by the signals from the host (CS0-, CS1-, DA2, DA1, DA0, DIOR- and DIOW-).
The Command Block Registers are used for sending commands to the device or posting status from the
device.
The Control Block Registers are used for device control and to post alternate status.
Copyright IBM Corp. 1997
D A 1
D A 0
R E A D ( D I O R )
x
x
D a t a b u s h i g h i m p e d * 1
C o n t r o l b l o c k r e g i s t e r s
x
x
D a t a b u s h i g h i m p e d
0
x
D a t a b u s h i g h i m p e d
1
0
A l t e r n a t e S t a t u s
1
1
D e v i c e A d d r e s s
C o m m a n d b l o c k r e g i s t e r s
0
0
D a t a
0
1
E r r o r R e g i s t e r
1
0
S e c t o r C o u n t
1
1
S e c t o r N u m b e r
1
1
* 2 L B A b i t s
0
0
C y l i n d e r L o w
0
0
* 2 L B A b i t s
0
1
C y l i n d e r H i g h
0
1
* 2 L B A b i t s 1 6 2 3
1
0
D e v i c e / H e a d
1
0
* 2 L B A b i t s 2 4 2 7
1
1
S t a t u s
x
x
I n v a l i d a d d r e s s
* 1 " i m p e d " s t a n d s f o r " i m p e d a n c e " .
* 2 M a p p i n g o f r e g i s t e r s i n L B A m o d e
A = s i g n a l a s s e r t e d
N = s i g n a l n e g a t e d
x = d o e s n o t m a t t e r w h i c h i t i s
F u n c t i o n s
W R I T E ( D I O W )
N o t u s e d
N o t u s e d
N o t u s e d
D e v i c e C o n t r o l
N o t u s e d
D a t a
F e a t u r e s
S e c t o r C o u n t
S e c t o r N u m b e r
0
7
* 2 L B A b i t s
C y l i n d e r L o w
8 1 5
* 2 L B A b i t s
C y l i n d e r H i g h
* 2 L B A b i t s 1 6 2 3
D e v i c e / H e a d
* 2 L B A b i t s 2 4 2 7
C o m m a n d
I n v a l i d a d d r e s s
0
7
8 1 5
61