SAM9263 Atmel Corporation, SAM9263 Datasheet - Page 110

• Manufacturer Part Number: SAM9263
• Manufacturer: Atmel Corporation

Specifications of SAM9263

• Flash (kbytes): 0 Kbytes
• Pin Count: 324
• Max. Operating Frequency: 240 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 160
• Ext Interrupts: 160
• Usb Transceiver: 3
• Usb Speed: Full Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 1
• Uart: 4
• Can: 1
• Ssc: 2
• Ethernet: 1
• Sd / Emmc: 2
• Graphic Lcd: Yes
• Video Decoder: No
• Camera Interface: Yes
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 96
• Self Program Memory: NO
• External Bus Interface: 2
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Fpu: No
• Mpu / Mmu: No / Yes
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

14.3.4
14.3.4.1
Figure 14-4. General Reset State
110
Backup Supply
AT91SAM9263
backup_nreset
Reset States
periph_nreset
Main Supply
POR output
POR output
proc_nreset
General Reset
(nrst_out)
RSTTYP
SLCK
NRST
MCK
The Reset State Manager handles the different reset sources and generates the internal reset
signals. It reports the reset status in the field RSTTYP of the Status Register (RSTC_SR). The
update of the field RSTTYP is performed when the processor reset is released.
A general reset occurs when VDDBU and VDDCORE are powered on. The backup supply POR
cell output rises and is filtered with a Startup Counter, which operates at Slow Clock. The pur-
pose of this counter is to make sure the Slow Clock oscillator is stable before starting up the
device. The length of startup time is hardcoded to comply with the Slow Clock Oscillator startup
time.
After this time, the processor clock is released at Slow Clock and all the other signals remain
valid for 3 cycles for proper processor and logic reset. Then, all the reset signals are released
and the field RSTTYP in RSTC_SR reports a General Reset. As the RSTC_MR is reset, the
NRST line rises 2 cycles after the backup_nreset, as ERSTL defaults at value 0x0.
When VDDBU is detected low by the Backup Supply POR Cell, all resets signals are immedi-
ately asserted, even if the Main Supply POR Cell does not report a Main Supply shutdown.
VDDBU only activates the backup_nreset signal.
The backup_nreset must be released so that any other reset can be generated by VDDCORE
(Main Supply POR output).
Figure 14-4
Startup Time
shows how the General Reset affects the reset signals.
XXX
EXTERNAL RESET LENGTH
= 2 cycles
Processor Startup
= 2 cycles
BMS Sampling
0x0 = General Reset
Freq.
Any
6249I–ATARM–3-Oct-11
XXX