Memory Controller Programming Model
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
12-49
12.7.12
DDR SDRAM Interval Configuration Register
(DDR_SDRAM_INTERVAL)
DDR_SDRAM_INTERVAL sets the number of DRAM clock cycles between bank refreshes
issued to the DDR SDRAMs. In addition, it specifies the number of DRAM cycles that a page is
maintained after it is accessed.
CKECTL
21–20
0
Clock Enable Control
Software uses this bit to clear or set globally all CKE
signals issued to DRAM. When software forces the value
driven on CKE, that value continues to be forced until
software clears the CKECTL bit. The DDR controller
continues to drive the CKE signals to the value forced by
software until another event causes the CKE signals to
change (that is, self refresh entry/exit, power down
entry/exit).
00 Software does not force the CKE
signals.
01 Software forces the CKE signals
to a low value.
10 Software forces the CKE signals
to a high value.
11 Reserved.
—
19–16
0
Reserved. Write to zero for future compatibility.
MDV
15–0
0
Mode Register Value
Specifies the value to present to the memory address pins
of the DDR controller during the MODE REGISTER SET,
EXTENDED MODE REGISTER SET, EXTENDED MODE
REGISTER SET 2, or EXTENDED MODE REGISTER
SET 3 command.
DDR_SDRAM_INTERVAL
DDR SDRAM Interval Configuration
Offset 0x0124
Register
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
REFINT
Type
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
—
BSTOPRE
Type
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 12-27. DDR_SDRAM_INTERVAL Bit Descriptions
Bit
Refresh Description
REFINT
31–16
0
Refresh Interval
Represents the number of memory bus clock cycles between refresh cycles. Depending on DDR
SDRAM CFG2 {NUM_PR] some number of rows are refreshed in each DDR SDRAM physical
bank during each refresh cycle. The value for REFINT depends on the specific SDRAMs used
and the interface clock frequency. Refreshes are not issued when REFINT is cleared to all 0s.
Table 12-26. DDR_SDRAM_MD_CNTL Bit Descriptions (Continued)
Bit Reset
Description
Settings
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...