SAM3S4B Atmel Corporation, SAM3S4B Datasheet - Page 442

• Manufacturer Part Number: SAM3S4B
• Manufacturer: Atmel Corporation

Specifications of SAM3S4B

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 64 MHz
• Cpu: Cortex-M3
• # Of Touch Channels: 23
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 79
• Ext Interrupts: 79
• Usb Transceiver: 1
• Quadrature Decoder Channels: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 3
• Twi (i2c): 2
• Uart: 4
• Ssc: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 10
• Adc Resolution (bits): 12
• Adc Speed (ksps): 1000
• Analog Comparators: 1
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 48
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

26.15 Write Protection Registers
To prevent any single software error that may corrupt PMC behavior, certain address spaces
can be write-protected by setting the WPEN bit in the
“PMC Write Protect Mode Register”
(PMC_WPMR).
If a write access to the protected registers is detected, then the WPVS flag in the PMC Write
Protect Status Register (PMC_WPSR) is set and the field WPVSRC indicates in which register
the write access has been attempted.
The WPVS flag is reset by writing the PMC Write Protect Mode Register (PMC_WPMR) with the
appropriate access key, WPKEY.
The protected registers are:
“PMC System Clock Enable Register” on page 444
“PMC System Clock Disable Register” on page 445
“PMC Peripheral Clock Enable Register 0” on page 447
“PMC Peripheral Clock Disable Register 0” on page 448
“PMC Clock Generator Main Oscillator Register” on page 450
“PMC Clock Generator PLLA Register” on page 453
“PMC Clock Generator PLLB Register” on page 454
“PMC Master Clock Register” on page 455
“PMC USB Clock Register” on page 456
“PMC Programmable Clock Register” on page 457
“PMC Fast Startup Mode Register” on page 463
“PMC Fast Startup Polarity Register” on page 464
“PMC Peripheral Clock Enable Register 1” on page 468
“PMC Peripheral Clock Disable Register 1” on page 469
“PMC Oscillator Calibration Register” on page 471
SAM3S
442
6500C–ATARM–8-Feb-11