Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
631
DDR SDRAM Memory Controller—Intel
®
81341 and 81342
18
0
2
Reserved
17:12
000000
2
RFC:
Refresh to Active and Refresh to Refresh period in MCLK periods
Equation 27. RFC = tRFC - 1
where tRFC is from SPD.
11:09
000
2
WR:
Write Recovery time in MCLK periods.
Equation 28. WR = tWR
where tWR is from SPD.
Note:
This parameter is not used by the DMCU.
08:04
00000
2
RC:
Active to Active and Active to Refresh period in MCLK periods.
Equation 29. RC = tRC - 1
where tRC is from SPD.
03:00
0000
2
WTRD:
Write to Read turnaround period in MCLK periods.
Equation 30. WTRD = tCAS - 1 + (BL/2) + tWTR
where BL = 4, tCAS and tWTR are from SPD.
Table 376. DDR SDRAM Control Register 1 - SDCR1 (Sheet 2 of 2)
Bit
Default
Description
PCI
IOP
Attributes
Attributes
28
24
20
16
12
8
4
0
31
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rv
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
na
rw
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
+1808H