AT91SAM7SE256B-AUR Atmel, AT91SAM7SE256B-AUR Datasheet - Page 209

• Manufacturer Part Number: AT91SAM7SE256B-AUR
• Description: IC ARM7 MCU FLASH 256K 128-LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7SE256B-AUR

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: EBI/EMI, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 88
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Processor Series: SAM7SE256
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 32 KB
• Interface Type: SPI, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 88
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: - 40 C to + 85 C
• Processor To Be Evaluated: AT91SAM7SE256B
• Supply Current (max): 60 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

23.6.5.2
Figure 23-8. Low-power Mode Behavior
6222F–ATARM–14-Jan-11
SDCKE
D[31:0]
A[12:0]
(input)
SDCS
SDCK
RAS
CAS
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 23-8
col b
Dna
col c
below.
Dnb
col d
SAM7SE512/256/32 Preliminary
Dnc
col e
Dnd
col f
Dne
Dnf
Low Power Mode
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