Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
637
DDR SDRAM Memory Controller—Intel
®
81341 and 81342
7.8.8
SDRAM 32-bit Region Size Register — S32SR
Defines the size of the 32-bit region located at the base of SDRAM Bank 0. This register
must be programmed with a size that is less than or equal to one half of the size of
DDR SDRAM Bank 0. Sizes are limited to binary sizes with a minimum size of 1MB.
Also, the DDR SDRAM type must be 64-bit, as defined by
. See also
“SDRAM Bank Size Register — SBSR” on page 635
and
Section 7.3.3.3, “DDR SDRAM Bank Sizes and Configurations” on page 578
.
This register is read back after being written, before the Intel XScale
®
microarchitecture performs transactions which address the DDR SDRAM.
Table 381. DDR SDRAM 32-bit Region Size Register — S32SR
Bit
Default
Description
31:30
00
2
Reserved
29:20 000H
32-bit Region Size — indicates the size of the 32-bit region at the base of Bank0 when a 64-bit data
bus width is implemented. This size is also the size of the invalid region adjacent to the 32-bit
region.
00 0000 0000 = no 32-bit region defined
00 0000 0001 = 1MB
00 0000 0010 = 2MB
00 0000 0100 = 4MB
00 0000 1000 = 8MB
00 0001 0000 = 16MB
00 0010 0000 = 32MB
00 0100 0000 = 64MB
00 1000 0000 = 128MB
01 0000 0000 = 256MB
10 0000 0000 = 512MB
all other values are reserved.
PCI
IOP
Attributes
Attributes
28
24
20
16
12
8
4
0
31
rv
na
rv
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
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
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
+1818H