SAM9G20 Atmel Corporation, SAM9G20 Datasheet - Page 94

• Manufacturer Part Number: SAM9G20
• Manufacturer: Atmel Corporation

Specifications of SAM9G20

• Flash (kbytes): 0 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 400 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): 1
• Uart: 7
• 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): 95
• 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): 0.9 to 1.1
• Fpu: No
• Mpu / Mmu: No/Yes
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Figure 14-8. Watchdog Reset
14.3.5
94
WDRPROC = 0
AT91SAM9G20
Reset State Priorities
Only if
periph_nreset
proc_nreset
When the WDRSTEN in WDT_MR bit is reset, the watchdog fault has no impact on the reset
controller.
The Reset State Manager manages the following priorities between the different reset sources,
given in descending order:
Particular cases are listed below:
(nrst_out)
• Backup Reset
• Wake-up Reset
• Watchdog Reset
• Software Reset
• User Reset
• When in User Reset:
• When in Software Reset:
• When in Watchdog Reset:
RSTTYP
wd_fault
NRST
SLCK
MCK
– A watchdog event is impossible because the Watchdog Timer is being reset by the
– A software reset is impossible, since the processor reset is being activated.
– A watchdog event has priority over the current state.
– The NRST has no effect.
– The processor reset is active and so a Software Reset cannot be programmed.
– A User Reset cannot be entered.
proc_nreset signal.
Freq.
Any
Any
Processor Startup
= 3 cycles
XXX
EXTERNAL RESET LENGTH
8 cycles (ERSTL=2)
0x2 = Watchdog Reset
6384E–ATARM–05-Feb-10