Intel
®
81341 and 81342—DDR SDRAM Memory Controller
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
650
Order Number: 315037-002US
7.8.22
DMCU Preemption Control Register — DMPCR
Enables Preemption of the South Internal Bus port and the direct attached ports
transaction when a North Internal Bus transaction is pending.
Table 395. DMCU Preemption Control Register - DMPCR
Bit
Default
Description
31:04
0
Reserved
03:00
0H
Preemption Data Phase Count:
Specifies the number of DDR data bursts that completes before
the current transactions are preempted. The count is based from the beginning of the transaction.
When a north internal bus transaction port request is detected after the count has been exceeded by
the current transaction, the transaction is preempted at the next burst length boundary. The current
transaction must be a non-north internal bus transaction.
0H = Disabled
4H = Enabled for 4 bursts (16 data phases for Burst Length=4, or 128Bytes for 64-bit data bus)
all other values are Reserved
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
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
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
®
microarchitecture Local Bus Address
offset
+186CH