ATmega168P Atmel Corporation, ATmega168P Datasheet - Page 176
ATmega168P
Manufacturer Part Number
ATmega168P
Description
Manufacturer
Atmel Corporation
Specifications of ATmega168P
Flash (kbytes)
16 Kbytes
Pin Count
32
Max. Operating Frequency
20 MHz
Cpu
8-bit AVR
# Of Touch Channels
16
Hardware Qtouch Acquisition
No
Max I/o Pins
23
Ext Interrupts
24
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
Yes
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
6
Input Capture Channels
1
Pwm Channels
6
32khz Rtc
Yes
Calibrated Rc Oscillator
Yes
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATmega168P-20AU
Manufacturer:
ATMEL
Quantity:
1 250
Company:
Part Number:
ATmega168P-20MU
Manufacturer:
ATMEL
Quantity:
12 000
Part Number:
ATmega168P-20MU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Company:
Part Number:
ATmega168PA-15AZ
Manufacturer:
VAC
Quantity:
120
Company:
Part Number:
ATmega168PA-15MZ
Manufacturer:
TOSHIBA
Quantity:
1 000
Company:
Part Number:
ATmega168PA-AU
Manufacturer:
Atmel
Quantity:
2 902
Part Number:
ATmega168PA-AU
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
Part Number:
ATmega168PA-MMH
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
20.3.1
176
ATmega48P/88P/168P
Internal Clock Generation – The Baud Rate Generator
Figure 20-2
Figure 20-2. Clock Generation Logic, Block Diagram
Signal description:
operation.
Internal clock generation is used for the asynchronous and the synchronous master modes of
operation. The description in this section refers to
The USART Baud Rate Register (UBRRn) and the down-counter connected to it function as a
programmable prescaler or baud rate generator. The down-counter, running at system clock
(f
the UBRRnL Register is written. A clock is generated each time the counter reaches zero. This
clock is the baud rate generator clock output (= f
baud rate generator clock output by 2, 8 or 16 depending on mode. The baud rate generator out-
put is used directly by the Receiver’s clock and data recovery units. However, the recovery units
use a state machine that uses 2, 8 or 16 states depending on mode set by the state of the
UMSELn, U2Xn and DDR_XCKn bits.
osc
), is loaded with the UBRRn value each time the counter has counted down to zero or when
txclk
rxclk
xcki
xcko
fosc
DDR_XCKn
XCKn
Pin
shows a block diagram of the clock generation logic.
xcko
xcki
OSC
Transmitter clock (Internal Signal).
Receiver base clock (Internal Signal).
Input from XCK pin (internal Signal). Used for synchronous slave
Clock output to XCK pin (Internal Signal). Used for synchronous master
operation.
XTAL pin frequency (System Clock).
Down-Counter
Prescaling
Register
UBRRn
Sync
UBRRn+1
foscn
Detector
UCPOLn
Edge
/2
Figure
osc
/(UBRRn+1)). The Transmitter divides the
/4
20-2.
/2
DDR_XCKn
U2Xn
0
1
0
1
0
1
1
0
8025M–AVR–6/11
UMSELn
txclk
rxclk