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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262-004US
647
Memory Controller—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
11.6.15
SDRAM Page Registers SDPR0-7
These registers hold the addresses of the eight pages that may be open. The valid bit is
included. For more details, see
Section 11.2.2.6, “Page Hit/Miss Determination” on
. These read-only registers are provided for testability purposes. The page
size is determined by the memory and data bus width as defined in
.
§ §
Register
Refresh Frequency Register - RFR
Bits
Name
Description
Default
Access
31:1
2
(Reserved)
00000H
RO
11:0
0
Refresh Interval: Programs the number of clocks that triggers a
request for a refresh cycle on the DDRI SDRAM interface. If all zeroes,
refresh cycles are disabled. See
Note:
If the memory interface is busy when the refresh counter
expires, it is possible for the MCU to generate more than one
refresh cycle when the memory interface becomes available.
000H
RO
Register Name:
SDRAM Page Registers - SDPR0, SDPR1, SDPR2, SDPR3,
SDPR4, SDPR5, SDPR6, SDPR7
Hex Offset Addresses:
0 — CC00 E550H
1 — CC00 E554H
2 — CC00 E558H
3 — CC00 E55CH
4 — CC00 E560H
5 — CC00 E564H
6 — CC00 E568H
7 — CC00 E56CH
Reset Hex Value:
0x0000 0000H
Register Description:
SDRAM Page Registers
Access: See below.
31
12 11
01 00
(Reserved)
Register
SDRAM Page Registers - SDPR0, SDPR1, SDPR2, SDPR3,
SDPR4, SDPR5, SDPR6, SDPR7
Bits
Name
Description
Default
Access
31:1
2
Page Address: Specifies the top 20 bits of an open page.
00000H
RW
11:0
1
(Reserved)
000H
RO
00
Page Valid: Indicates if the page address in bits 31 to 12 is a valid
page.
0 = Page Invalid
1 = Page Valid
0
2
RW