Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
725
Peripheral Bus Interface Unit—Intel
®
81341 and 81342
9.3.8
PBI Drive Strength Control Register — PBDSCR
This register is used to manually control slew rate and drive strength for all of 81341
and 81342 pins with the exception of high-speed serial interfaces, the SDRAM
interface, and the PCI-X interface.
Note:
By default, this register is
not
required to program. This register should not be
programmed to a different value without consulting the 81341 and 81342 where the
appropriate values are specified.
Table 441. PBI Drive Strength Control Register — PBDSCR
Bit
Default
Description
31:20
000H
Reserved
19:16
0011
2
Pull-Down Slew Rate Control (NSLW[3:0]): T
unes the slew rate of the n-drivers of all the pins
with the exception of the high speed serial interfaces, the SDRAM interface and the PCI-X interface.
15:12
0011
2
Pull-Up Slew Rate Control (PSLW[3:0]): T
unes the slew rate of the p-drivers of all the pins with
the exception of the high speed serial interfaces, the SDRAM interface and the PCI-X interface.
11:06
001100
2
Pull-Down Drive Strength (NDRV[5:0]): P
rograms the strength of the n-drivers of all the pins
with the exception of the high speed serial interfaces, the SDRAM interface and the PCI-X interface.
05:00
010110
2
Pull-Up Drive Strength (PDRV[5:0]): This field
programs the p-driver strength of all the pins
with the exception of the high speed serial interfaces, the SDRAM interface and the PCI-X interface.
PCI
IOP
Attributes
Attributes
28
24
20
16
12
8
4
0
31
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
NA = Not Accessible
Intel XScale
®
processor Local Bus Address offset
+2080H