
. . . . .
M E M O R Y C O N T R O L L E R
Dynamic Memory Active to Active Command Period register
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243
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D y n a m i c M e m o r y A c t i v e t o A c t i v e C o m m a n d P e r i o d r e g i s t e r
Address: A070 0048
The Dynamic Memory Active to Active Command Period register allows you to
program the active to active command period, t
RC
. 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 datasheets as t
RC
.
Note:
The Dynamic Memory Active to Active Command period register is used for all
four dynamic memory chip selects. The worst case value for all chip selects
must be programmed.
Register
Register bit
assignment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D y n a m i c M e m o r y A u t o R e f r e s h P e r i o d r e g i s t e r
Address: A070 004C
The Dynamic Memory Auto Refresh Period register allows you to program the auto-
refresh period and the auto-refresh to active command period, t
RFC
. It is
recommended that this register be modified during 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
datasheets as t
RFC
or t
RC
.
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
RC
Bits
Access
Mnemonic
Description
D31:05
N/A
Reserved
N/A (do not modify)
D04:00
R/W
RC
Active to active command period (t
RC
)
0x0–0x1E
n+1 clock cycles, where the delay is in
clk_out
cycles.
0x1F
32 clock cycles (reset value on
reset_n
)
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
Page 4: ......
Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...