Table 43 - PC/AT and PS/2 Available Registers
Available Registers
Base + Address
PC-AT
PS/2 (Model 30) Access Permitted
Access to these registers DOES NOT wake up the part
00H
01H
02H
03H
04H
06H
07H
07H
----
----
SRA
SRB
R
R
DOR (1)
---
DOR (1)
---
R/W
---
W
DSR (1)
---
DSR (1)
---
---
R
DIR
DIR
CCR
CCR
W
Access to these registers wakes up the part
04H
05H
MSR
Data
MSR
Data
R
R/W
Note 1: Writing to the DOR or DSR does not wake up the part, however, writing any of the motor
enable bits or doing a software reset (via DOR or DSR reset bits) will wake up the part.
Table 44 - State of System Pins in Auto Powerdown
System Pins
State in Auto Powerdown
Input Pins
IOR
IOW
Unchanged
Unchanged
Unchanged
Unchanged
Unchanged
Unchanged
Unchanged
Unchanged
A[0:9]
D[0:7]
RESET
IDENT
DACK
TC
Output Pins
FINTR
DB[0:7]
FDRQ
Unchanged (low)
Unchanged
Unchanged (low)
111
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