ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 287

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.3.4
6430D–ATARM–25-Mar-11
Using Backup Batteries/Backup Supply
The product can be used with or without backup batteries, or more generally a backup supply.
When a backup supply is used (See
mode and no other external supply is applied on the chip. In this case the user needs to clear
VDDIORDY bit in the Supply Controller Mode Register (SUPC_MR) at least two slow clock peri-
ods before VDDIO voltage is removed. When waking up from Backup mode, the programmer
needs to set VDDIORDY.
Figure 19-2. Separated Backup Supply Powering Scheme
Note:
When a separated backup supply for VDDBU is not used (See
voltage applied on VDDIO is kept, all of the I/O configurations (i.e. WKUP pin configuration) are
kept during backup mode. When not using backup batteries, VDDIORDY is set so the user does
not need to program it.
Restrictions: With Main Supply < 3V, some peripherals such as USB and ADC might not be oper-
ational. Refer to the DC Characteristics of the product for actual possible ranges for such
peripherals.
Main Supply (1.8V-3.6V)
Figure
Backup Batteries
19-2), only VDDBU voltage is present in Backup
VDDUTMI
VDDANA
VDDCORE
VDDBU
VDDIO
FWUP
VDDIN
VDDPLL
VDDOUT
SHDN
Figure
SAM3U Series
19-3), since the external
Regulator
Voltage
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