SAM3N2A Atmel Corporation, SAM3N2A Datasheet - Page 487

• Manufacturer Part Number: SAM3N2A
• Manufacturer: Atmel Corporation

Specifications of SAM3N2A

• Flash (kbytes): 128 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 48 MHz
• Cpu: Cortex-M3
• # Of Touch Channels: 23
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 47
• Ext Interrupts: 47
• Quadrature Decoder Channels: 2
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 2
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 16
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• 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: no / no
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

28.10.5.4
Figure 28-28. Clock Synchronization in Read Mode
Notes:
11011A–ATARM–04-Oct-10
11011A–ATARM–04-Oct-10
TWI_THR
TXCOMP
SVREAD
Clock Synchronization in Read Mode
SCLWS
SVACC
TXRDY
TWCK
1. TXRDY is reset when data has been written in the TWI_THR to the shift register and set when this data has been acknowl-
2. At the end of the read sequence, TXCOMP is set after a STOP or after a REPEATED_START + an address different from
3. SCLWS is automatically set when the clock synchronization mechanism is started.
edged or non acknowledged.
SADR.
Clock Synchronization
1
2
S
S
The data is memorized in TWI_THR until a new value is written
TWI_THR is transmitted to the shift register
The clock is stretched after the ACK, the state of TWD is undefined during clock stretching
As soon as a START is detected
SADR
In both read and write modes, it may happen that TWI_THR/TWI_RHR buffer is not filled /emp-
tied before the emission/reception of a new character. In this case, to avoid sending/receiving
undesired data, a clock stretching mechanism is implemented.
The clock is tied low if the shift register is empty and if a STOP or REPEATED START condition
was not detected. It is tied low until the shift register is loaded.
Figure 28-28 on page 487
DATA0
DATA0
R
Write THR
A
1
DATA0
A
describes the clock synchronization in Read mode.
DATA1
DATA1
CLOCK is tied low by the TWI
as long as THR is empty
A
XXXXXXX
2
DATA2
DATA2
Ack or Nack from the master
NA
S
SAM3N
SAM3N
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