ATmega165P Atmel Corporation, ATmega165P Datasheet - Page 194

• Manufacturer Part Number: ATmega165P
• Manufacturer: Atmel Corporation

Specifications of ATmega165P

• Flash (kbytes): 16 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

8019K–AVR–11/10
Figure 19-5. Two-wire Mode, Typical Timing Diagram
Referring to the timing diagram
1. The a start condition is generated by the Master by forcing the SDA low line while the
2. In addition, the start detector will hold the SCL line low after the Master has forced an
3. The Master set the first bit to be transferred and releases the SCL line (C). The Slave
4. After eight bits are transferred containing slave address and data direction (read or
5. If the Slave is addressed it holds the SDA line low during the acknowledgment cycle
6. Multiple bytes can now be transmitted, all in same direction, until a stop condition is given
If the Slave is not able to receive more data it does not acknowledge the data byte it has last
received. When the Master does a read operation it must terminate the operation by force the
acknowledge bit low after the last byte transmitted.
Figure 19-6. Start Condition Detector, Logic Diagram
SDA
SCL
SCL line is high (A). SDA can be forced low either by writing a zero to bit 7 of the Shift
Register, or by setting the corresponding bit in the PORT Register to zero. Note that the
Data Direction Register bit must be set to one for the output to be enabled. The slave
device’s start detector logic
Flag. The flag can generate an interrupt if necessary.
negative edge on this line (B). This allows the Slave to wake up from sleep or complete
its other tasks before setting up the Shift Register to receive the address. This is done by
clearing the start condition flag and reset the counter.
samples the data and shift it into the Serial Register at the positive edge of the SCL
clock.
write), the Slave counter overflows and the SCL line is forced low (D). If the slave is not
the one the Master has addressed, it releases the SCL line and waits for a new start
condition.
before holding the SCL line low again (that is, the Counter Register must be set to 14
before releasing SCL at (D)). Depending of the R/W bit the Master or Slave enables its
output. If the bit is set, a master read operation is in progress (that is, the slave drives the
SDA line) The slave can hold the SCL line low after the acknowledge (E).
by the Master (F). Or a new start condition is given.
Write( USISIF)
A B
S
SDA
SCL
C
ADDRESS
1 - 7
R/W
8
(Figure
(Figure
D
ACK
19-5), a bus transfer involves the following steps:
19-6) detects the start condition and sets the USISIF
9
E
DATA
1 - 8
D Q
CLR
ACK
9
DATA
1 - 8
D Q
ATmega165P
CLR
ACK
9
USISIF
CLOCK
HOLD
P
F
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