NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 229 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
SDRAM Controller Refresh Control Register (SDIC_REFCTL)
Register
Offset
R/W
Description
Reset Value
SDIC_REFCTL
S 0x008 R/W
SDRAM Controller Refresh Control Register
0x0000_80FF
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
REF_EN
REFRAT
7
6
5
4
3
2
1
0
REFRAT
Bits
Description
[31:24]
Reserved
Reserved.
[15]
REF_EN
Refresh Period Counter Enable
This bit controls if the refresh period counter is enabled.
If refresh period counter is disabled, the SDRAM controller would never issue auto-refresh
command to SDRAM automatically. However, if refresh period counter is enabled, the SDRAM
controller will issue auto-refresh command to SDRAM automatically once the refresh period
counter is equal to REFRATE.
0 = Refresh period counter is disabled.
1 = Refresh period counter is enabled to trigger SDRAM controller to issue auto-refresh
command to SDRAM periodically. (Default)
[14:0]
REFRATE
Refresh Count Value
This field defines the period for SDRAM controller to generate the auto-refresh command to
SDRAM.
The SDRAM controller will issue an auto-refresh cycle to SDRAM automatically for every period
programmed in the REFRAT field when the REF_EN bit of is set.
The refresh period is calculated as Period = REFRAT / fSCLK.
The fSCLK is the frequency of external crystal for chip.