AT91SAM9R64-CU-999 Atmel, AT91SAM9R64-CU-999 Datasheet - Page 215

• Manufacturer Part Number: AT91SAM9R64-CU-999
• Description: IC MCU ARM9 64K SRAM 144LFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9R64-CU-999

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 240MHz
• Connectivity: EBI/EMI, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: AC'97, POR, PWM, WDT
• Number Of I /o: 49
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: ROM
• Ram Size: 72K x 8
• Voltage - Supply (vcc/vdd): 1.08 V ~ 1.32 V
• Data Converters: A/D 3x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LFBGA
• Processor Series: AT91SAMx
• Core: ARM926EJ-S
• Data Bus Width: 32 bit
• Data Ram Size: 64 KB
• Interface Type: SPI, TWI, UART
• Maximum Clock Frequency: 240 MHz
• Number Of Programmable I/os: 118
• Operating Supply Voltage: 1.65 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM9RL-EK
• Minimum Operating Temperature: - 40 C
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

23.5.6
Figure 23-6. Self-refresh Mode Behavior
6289C–ATARM–28-May-09
SDRAMC_A[12:0]
SDRAMC_SRR
SDCKE
SDWE
SDCK
SDCS
Write
Self-refresh Mode
RAS
CAS
SRCB = 1
This mode is selected by programming the LPCB field to 1 in the SDRAMC Low Power Register.
In self-refresh mode, the SDRAM device retains data without external clocking and provides its
own internal clocking, thus performing its own auto-refresh cycles. All the inputs to the SDRAM
device become “don’t care” except SDCKE, which remains low. As soon as the SDRAM device
is selected, the SDRAM Controller provides a sequence of commands and exits self-refresh
mode.
Some low-power SDRAMs (e.g., mobile SDRAM) can refresh only one quarter or a half quarter
or all banks of the SDRAM array. This feature reduces the self-refresh current. To configure this
feature, Temperature Compensated Self Refresh (TCSR), Partial Array Self Refresh (PASR)
and Drive Strength (DS) parameters must be set in the Low Power Register and transmitted to
the low-power SDRAM during initialization.
After initialization, as soon as PASR/DS/TCSR fields are modified and self-refresh mode is acti-
vated, the Extended Mode Register is accessed automatically and PASR/DS/TCSR bits are
updated before entry into self-refresh mode.
The SDRAM device must remain in self-refresh mode for a minimum period of t
remain in self-refresh mode for an indefinite period. This is described in
AT91SAM9R64/RL64 Preliminary
Self Refresh Mode
to the SDRAM Controller
Access Request
T
Figure
XSR
= 3
23-6.
RAS
Row
and may
215