Digi NS9750 User Manual
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M e m o r y C o n t r o l l e r
Dynamic Memory Self-refresh Exit Time register
Address: A070 0038
The Dynamic Memory Self-refresh Exit Time register allows you to program the self-
refresh exit time, t
SREX
. It is recommended that this register be modified during
system initialization, or when there are no current or outstanding transactions. Wait
until the memory controller is idle, then enter low-power or disabled mode. This
value normally is found in SDRAM data sheets as t
SREX
.
Note:
The Dynamic Memory Self-refresh Exit Time register is used for all four
dynamic memory chip selects. The worst case value for all chip selects
must be programmed.
Register bit assignment
Bits
Access
Mnemonic
Description
D31:04
N/A
Reserved
N/A (do not modify)
D03:00
R/W
SREX
Self-refresh exit time (t
SREX
)
0x0–0xE
n+1 clock cycles, where the delay is in
CLK
cycles.
0xF
16 clock cycles (reset value on
reset_n
)
Table 146: Dynamic Memory Self-refresh Exit Time register
13
12
11
10
9
8
7
6
5
4
3
2
1
0
15
14
31
29
28
27
26
25
24
23
22
21
20
19
18
17
16
30
Reserved
Reserved
SREX