Intel IXP42X Personal Computer User Manual


 
Intel
®
IXP42X product line and IXC1100 control plane processors—Intel XScale
®
Processor
Intel
®
IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
80 Order Number: 252480-006US
3.5.1.4 Register 3: Domain Access Control Register
3.5.1.5 Register 4: Reserved
Register 4 is reserved. Reading and writing this register yields unpredictable results.
3.5.1.6 Register 5: Fault Status Register
The Fault Status Register (FSR) indicates which fault has occurred, which could be
either a prefetch abort or a data abort. Bit 10 extends the encoding of the status field
for prefetch aborts and data aborts. The definition of the extended status field is found
in “Event Architecture” on page 154. Bit 9 indicates that a debug event occurred and
the exact source of the event is found in the debug control and status register (CP14,
register 10). When bit 9 is set, the domain and extended status field are undefined.
Upon entry into the prefetch abort or data abort handler, hardware will update this
register with the source of the exception. Software is not required to clear these fields.
Table 15. Domain Access Control Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
reset value: unpredictable
Bits Access Description
31:0 Read / Write
Access permissions for all 16 domains - The meaning
of each field can be found in the ARM* Architecture
Reference Manual.
Table 16. Fault Status Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
X D 0 Domain Status
reset value: unpredictable
Bits Access Description
31:11 Read-unpredictable / Write-as-Zero Reserved
10 Read / Write
Status Field Extension (X)
This bit is used to extend the encoding of the Status field,
when there is a prefetch abort and when there is a data
abort. The definition of this field can be found in “Event
Architecture” on page 154
9Read / Write
Debug Event (D)
This flag indicates a debug event has occurred and that
the cause of the debug event is found in the MOE field of
the debug control register (CP14, register 10)
8 Read-as-zero / Write-as-Zero = 0
7:4 Read / Write
Domain - Specifies which of the 16 domains was being
accessed when a data abort occurred
3:0 Read / Write Status - Type of data access being attempted