Intel
®
81341 and 81342—Peripheral Bus Interface Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
726
Order Number: 315037-002US
9.3.9
Processor Frequency Register - PFR
This register indicates the clock frequencies of the Intel XScale
®
processor and the
internal buses of the 81341 and 81342. For products with two enabled Intel XScale
®
processors, the cores run at the same clock frequency.
Table 442. Processor Frequency Register - PFR
Bit
Default
Description
31:21
xH
Reserved. Values read are undefined.
20:19 Dependent on the
Product Type.
XSI Bus Frequency Status. Note that the internal bus frequency is set at manufacturing
time and is product dependent, which means that not all the frequencies as listed below
are supported.
Bits Ratio
00
2
2:1 - Indicates that the Internal bus is running at the Core Frequency divided by 2.
01
2
3:1 - Indicates that the Internal bus is running at the Core Frequency divided by 3.
10
2
4:1 - Indicates that the Internal bus is running at the Core Frequency divided by 4.
11
2
Reserved
18:16 Dependent on the
Product Type.
Intel XScale
®
processor
Frequency Status. Note that the
Intel XScale
®
processor
frequency is
set at manufacturing time and is product dependent, which means that not all the
frequencies as listed below are supported.
Bits Core Frequency
000
2
600 MHz
001
2
667 MHz
010
2
800 MHz
011
2
933 MHz
100
2
1000 MHz
101
2
1200 MHz
110
2
Reserved
111
2
Reserved
15:00
xH
Reserved. Values read are undefined.
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
ro
na
ro
na
ro
na
ro
na
ro
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
na
rv
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
+2180H