ATMEGA169P-16AU Atmel, ATMEGA169P-16AU Datasheet - Page 180

• Manufacturer Part Number: ATMEGA169P-16AU
• Description: IC AVR MCU 16K 16MHZ IND 64-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA169P-16AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Processor Series: ATMEGA16x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI/USART/USI
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRBFLY
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Package: 64TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• For Use With: ATSTK600-TQFP64 - STK600 SOCKET/ADAPTER 64-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEMATAVRBFLY - KIT EVALUATION AVR BUTTERFLYATSTK502 - MOD EXPANSION AVR STARTER 500ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.7
19.7.1
8018P–AVR–08/10
Data Reception – The USART Receiver
Receiving Frames with 5 to 8 Data Bits
The USART Receiver is enabled by writing the Receive Enable (RXENn) bit in the UCSRnB
Register to one. When the Receiver is enabled, the normal pin operation of the RxD pin is over-
ridden by the USART and given the function as the Receiver’s serial input. The baud rate, mode
of operation and frame format must be set up once before any serial reception can be done. If
synchronous operation is used, the clock on the XCK pin will be used as transfer clock.
The Receiver starts data reception when it detects a valid start bit. Each bit that follows the start
bit will be sampled at the baud rate or XCK clock, and shifted into the Receive Shift Register until
the first stop bit of a frame is received. A second stop bit will be ignored by the Receiver. When
the first stop bit is received, that is, a complete serial frame is present in the Receive Shift Regis-
ter, the contents of the Shift Register will be moved into the receive buffer. The receive buffer
can then be read by reading the UDRn I/O location.
The following code example shows a simple USART receive function based on polling of the
Receive Complete (RXCn) Flag. When using frames with less than eight bits the most significant
bits of the data read from the UDRn will be masked to zero. The USART has to be initialized
before the function can be used.
Note:
The function simply waits for data to be present in the receive buffer by checking the RXCn Flag,
before reading the buffer and returning the value.
Assembly Code Example
C Code Example
USART_Receive:
unsigned char USART_Receive( void )
{
}
; Wait for data to be received
sbis UCSR0A, RXC0
rjmp USART_Receive
; Get and return received data from buffer
in
ret
/* Wait for data to be received */
while ( !(UCSR0A & (1<<RXC0)) )
/* Get and return received data from buffer */
return UDR0;
1.
See ”About Code Examples” on page 10.
r16, UDR0
;
(1)
(1)
ATmega169P
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