SAM9XE512 Atmel Corporation, SAM9XE512 Datasheet - Page 30

• Manufacturer Part Number: SAM9XE512
• Manufacturer: Atmel Corporation

Specifications of SAM9XE512

• Flash (kbytes): 512 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 180 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 96
• Ext Interrupts: 96
• Usb Transceiver: 3
• Usb Speed: Full Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 2
• Uart: 6
• Ssc: 1
• Ethernet: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: Yes
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 312
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 1.65 to 1.95
• Fpu: No
• Mpu / Mmu: No / Yes
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

9.2
9.3
9.4
30
Reset Controller
Brownout Detector and Power-on Reset
Shutdown Controller
AT91SAM9XE128/256/512 Preliminary
The AT91SAM9XE128/256/512 embeds one brownout detection circuit and power-on reset
cells. The power-on reset are supplied with and monitor VDDCORE and VDDBU.
Signals (flash_poe and flash_wrdis) are provided to the Flash to prevent any code corruption
during power-up or power-down sequences or if brownouts occur on the VDDCORE power
supply.
The power-on reset cell has a limited-accuracy threshold at around 1.5V. Its output remains low
during power-up until VDDCORE goes over this voltage level. This signal goes to the reset con-
troller and allows a full re-initialization of the device.
The brownout detector monitors the VDDCORE level during operation by comparing it to a fixed
trigger level. It secures system operations in the most difficult environments and prevents code
corruption in case of brownout on the VDDCORE.
When the brownout detector is enabled and VDDCORE decreases to a value below the trigger
level (Vbot-), the brownout output is immediately activated. For more details on Vbot, see the
table “Brownout Detector Characteristics” in the section “AT91SAM9XE128/256/512 Electrical
Characteristics” in the full datasheet.
When VDDCORE increases above the trigger level (Vbot+, defined as Vbot + Vhyst), the reset
is released. The brownout detector only detects a drop if the voltage on VDDCORE stays below
the threshold voltage for longer than about 1µs.
The VDDCORE threshold voltage has a hysteresis of about 50 mV typical, to ensure spike free
brownout detection. The typical value of the brownout detector threshold is 1.55V with an accu-
racy of ± 2% and is factory calibrated.
The brownout detector is low-power, as it consumes less than 12 µA static current. However, it
can be deactivated to save its static current. In this case, it consumes less than 1 µA. The deac-
tivation is configured through the GPNVMBit[1] of the Flash.
Additional information can be found in the “Electrical Characteristics” section of the product
datasheet.
• Based on two Power-on reset cells
• Status of the last reset
• Controls the internal resets and the NRST pin output
• Shutdown and Wake-Up logic
– One on VDDBU and one on VDDCORE
– Either general reset (VDDBU rising), wake-up reset (VDDCORE rising), software
– Allows shaping a reset signal for the external devices
– At reset the NRST pin is an output
– Software programmable assertion of the SHDN pin
– Deassertion Programmable on a WKUP pin level change or on alarm
reset, user reset or watchdog reset
6254C–ATARM–22-Jan-10