AT91RM9200-CI-002 Atmel, AT91RM9200-CI-002 Datasheet - Page 204

• Manufacturer Part Number: AT91RM9200-CI-002
• Description: IC ARM9 MCU 256 BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91RM9200-CI-002

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 180MHz
• Connectivity: EBI/EMI, Ethernet, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: POR
• Number Of I /o: 122
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: ROM
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

19.6.5.2
Figure 19-8. Low-power Mode Behavior
204
SDCKE
D[31:0]
A[12:0]
SDCS
SDCK
(input)
RAS
CAS
AT91RM9200
Low-power Mode
Row n
Low-power mode is used in power-down mode, i.e., when no access to the SDRAM device is
possible. In this mode, power consumption is greater than in self-refresh mode. This state is sim-
ilar to normal mode (No low-power mode/No self-refresh mode), but the SDCKE pin is low and
the input and output buffers are deactivated as soon as the SDRAM device is no longer accessi-
ble. In contrast to self-refresh mode, the SDRAM device cannot remain in low-power mode
longer than the refresh period (64 ms for a whole device refresh operation). As no auto-refresh
operations are performed in this mode, the SDRAM Controller carries out the refresh operation.
In order to exit low-power mode, a NOP command is required. The exit procedure is faster than
in self-refresh mode.
When self-refresh mode is enabled, it is recommended to avoid enabling low-power mode.
When low-power mode is enabled, it is recommended to avoid enabling self-refresh mode.
This is described in
T
RCD
= 3
col a
CAS = 2
Figure 19-8
col b
Dna
col c
below.
Dnb
col d
Dnc
col e
Dnd
col f
Dne
Dnf
1768I–ATARM–09-Jul-09
Low Power Mode