Example – Digi NS9750 User Manual
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M e m o r y C o n t r o l l e r
Example
Static memory read/write time = 16 us
CLK frequency = 50 MHz
This value must be programmed into the Static Memory Extended Wait register:
(16 x 10
-6
x 50 x 10
6
/ 16) - 1 = 49
Dynamic Memory Configuration 0–3 registers
Address: A070 0100 / 0120 / 0140 / 0160
The Dynamic Memory Configuration 0–3 registers allow you to program the
configuration information for the relevant dynamic memory chip select. These
registers are usually modified only during system initialization.
Register bit assignment
Bits
Access
Mnemonic
Description
D31:21
N/A
Reserved
N/A (do not modify)
D20
R/W
Protect
Write protect
0
Writes not protected (reset value on
reset_n
)
1
Write protected
D19
R/W
BDMC
Buffer enable
0
Buffer disabled for accesses to this chip select (reset value on
reset_n
)
1
Buffer enabled for accesses to this chip select. The buffers must
be disabled during SDRAM initialization. The buffers must be
enabled during normal operation.
D18:15
N/A
Reserved
N/A (do not modify)
Table 156: Dynamic Memory Configuration 0–3 registers
Rsvd
13
12
11
10
9
8
7
6
5
4
3
2
1
0
15
14
Rsvd
AM
31
29
28
27
26
25
24
23
22
21
20
19
18
17
16
30
Reserved
Protect BDMC
Reserved
AM1
Reserved
MD
Reserved