SAM9G25 Atmel Corporation, SAM9G25 Datasheet - Page 922

• Manufacturer Part Number: SAM9G25
• Manufacturer: Atmel Corporation

Specifications of SAM9G25

• Flash (kbytes): 0 Kbytes
• Pin Count: 247
• Max. Operating Frequency: 400 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 105
• Ext Interrupts: 105
• Usb Transceiver: 3
• Usb Speed: Hi-Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 3
• Uart: 7
• Lin: 4
• Ssc: 1
• Ethernet: 1
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: Yes
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 440
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: DDR2/LPDDR, SDRAM/LPSDR
• 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
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

41.6
41.6.1
Figure 41-2. Sequence of ADC conversions
41.6.2
41.6.3
922
922
(Hard or Soft)
Trigger event
Functional Description
ADC_Start
ADCClock
ADC_SEL
ADC_ON
ADC_eoc
SAM9G25
SAM9G25
Analog-to-digital Conversion
Conversion Reference
Conversion Resolution
DRDY
LCDR
The ADC uses the ADC Clock to perform conversions. Converting a single analog value to a 10-
bit digital data requires Tracking Clock cycles as defined in the field TRACKTIM of the
Mode Register” on page 930
same register. The ADC Clock frequency is selected in the PRESCAL field of the Mode Register
(ADC_MR). The tracking phase starts during the conversion of the previous channel. If the track-
ing time is longer than the conversion time, the tracking phase is extended to the end of the
previous conversion.
The ADC clock range is between MCK/2, if PRESCAL is 0, and MCK/512, if PRESCAL is set to
255 (0xFF). PRESCAL must be programmed in order to provide an ADC clock frequency
according to the parameters given in the product Electrical Characteristics section.
The conversion is performed on a full range between 0V and the reference voltage pin ADVREF.
Analog inputs between these voltages convert to values based on a linear conversion.
The ADC supports 8-bit or 10-bit resolutions. The 8-bit selection is performed by setting the
LOWRES bit in the ADC Mode Register (ADC_MR). By default, after a reset, the resolution is
the highest and the DATA field in the data registers is fully used. By setting the LOWRES bit, the
ADC switches to the lowest resolution and the conversion results can be read in the lowest sig-
nificant bits of the data registers. The two highest bits of the DATA field in the corresponding
ADC_CDR register and of the LDATA field in the ADC_LCDR register read 0.
(and tracking of CH0)
CH0
Start Up Time
Conversion of CH0
and Transfer Clock cycles as defined in the field TRANSFER of the
CH0
CH1
Tracking of CH1
Conversion of CH1
CH2
CH1
Tracking of CH2
11032A–ATARM–27-Jul-11
11032A–ATARM–27-Jul-11
“ADC