SAM9G20 Atmel Corporation, SAM9G20 Datasheet - Page 681

• 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

35.7.5
11053B–ATARM–22-Sep-11
11053B–ATARM–22-Sep-11
Write Protected Registers
Figure 35-11. Slave Mode Functional Bloc Diagram
To prevent any single software error that may corrupt SPI behavior, the registers listed below
can be write-protected by setting the SPIWPEN bit in the SPI Write Protection Mode Register
(SPI_WPMR).
If a write access in a write-protected register is detected, then the SPIWPVS flag in the SPI
Write Protection Status Register (SPI_WPSR) is set and the field SPIWPVSRC indicates in
which register the write access has been attempted.
The SPIWPVS flag is automatically reset after reading the SPI Write Protection Status Register
(SPI_WPSR).
List of the write-protected registers:
Section 35.8.2 ”SPI Mode Register”
Section 35.8.9 ”SPI Chip Select Register”
SPCK
MOSI
NSS
SPIDIS
SPIEN
SPIENS
SPI_CSR0
LSB
NCPHA
CPOL
BITS
Shift Register
Clock
SPI
SPI_RDR
SPI_TDR
RD
TD
MSB
OVRES
RDRF
TDRE
SAM9G35
SAM9G35
MISO
681
681