
. . . . .
M E M O R Y C O N T R O L L E R
Static memory controller
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207
2
When the power-on reset (
reset_n
) goes inactive, the processor starts booting
from
0x00000000
in memory.
3
The software programs the optimum delay values in flash memory so the boot
code can run at full speed.
4
The code branches to chip select 1 so the code can continue executing from the
non-remapped memory location.
5
The appropriate values are programmed into the memory controller to
configure chip select 4, and the memory device is initialized.
6
The address mirroring is disabled by clearing the address mirror (M) field in the
Control register.
7
The ARM reset and interrupt vectors are copied from flash memory to SDRAM
that can then be accessed at address
0x00000000
.
8
More boot, initialization, or application code is executed.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S t a t i c m e m o r y c o n t r o l l e r
This table shows configurations for the static memory controller with different
types of memory devices. See “StaticMemory Configuration 0–3 registers” on
page 251 for more information.
Device
Write protect
Page mode
Buffer
ROM
Enabled
Disabled
Disabled
a
Page mode ROM
Enabled
Enabled
Enabled
a
Extended wait ROM
Enabled
Disabled
Disabled
a
SRAM
Disabled (or enabled)
b
Disabled
Disabled
a
Page mode SRAM
Disabled (or enabled)
b
Enabled
Enabled
a
Extended wait SRAM
Disabled (or enabled)
b
Disabled
Disabled
a
Flash
Disabled or (enabled)
b
Disabled
Disabled
c
Page mode flash
Disabled or (enabled)
b
Enabled
Enabled
c
Extended wait flash
Disabled or (enabled)
b
Disabled
Disabled
a
Memory mapped peripheral
Disabled (or enabled)
b
Disabled
Disabled
a
Enabling the buffers means that any access causes the buffer to be used. Depending on the
application, this can provide performance improvements. Devices without async-page-mode
support generally work better with the buffer disabled. Again, depending on the application, this
can provide performance improvements.
b
SRAM and Flash memory devices can be write-protected if required.
c
Buffering must be disabled when performing Flash memory commands and during writes.
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...