ATMEGA169PV-8AU Atmel, ATMEGA169PV-8AU Datasheet - Page 194

• Manufacturer Part Number: ATMEGA169PV-8AU
• Description: IC AVR MCU 16K 8MHZ 1.8V 64-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA169PV-8AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• 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): 1.8 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: 8 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 8MHz
• Total Internal Ram Size: 1KB
• # I/os (max): 54
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 2.5/3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 1.8V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Package Type: TQFP
• Package: 64TQFP
• Family Name: ATmega
• Maximum Speed: 8 MHz
• Operating Supply Voltage: 2.5|3.3|5 V
• Controller Family/series: AVR MEGA
• No. Of I/o's: 54
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 1KB
• Cpu Speed: 8MHz
• Rohs Compliant: Yes
• 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

19.11 USART Register Description
19.11.1
19.11.2
8018P–AVR–08/10
UDRn – USART I/O Data Register
UCSRnA – USART Control and Status Register A
The USART Transmit Data Buffer Register and USART Receive Data Buffer Registers share the
same I/O address referred to as USART Data Register or UDRn. The Transmit Data Buffer Reg-
ister (TXB) will be the destination for data written to the UDRn Register location. Reading the
UDRn Register location will return the contents of the Receive Data Buffer Register (RXB).
For 5-, 6-, or 7-bit characters the upper unused bits will be ignored by the Transmitter and set to
zero by the Receiver.
The transmit buffer can only be written when the UDREn Flag in the UCSRnA Register is set.
Data written to UDRn when the UDREn Flag is not set, will be ignored by the USART Transmit-
ter. When data is written to the transmit buffer, and the Transmitter is enabled, the Transmitter
will load the data into the Transmit Shift Register when the Shift Register is empty. Then the
data will be serially transmitted on the TxD pin.
The receive buffer consists of a two level FIFO. The FIFO will change its state whenever the
receive buffer is accessed. Due to this behavior of the receive buffer, do not use Read-Modify-
Write instructions (SBI and CBI) on this location. Be careful when using bit test instructions
(SBIC and SBIS), since these also will change the state of the FIFO.
• Bit 7 – RXCn: USART Receive Complete n
This flag bit is set when there are unread data in the receive buffer and cleared when the receive
buffer is empty (that is, does not contain any unread data). If the Receiver is disabled, the
receive buffer will be flushed and consequently the RXCn bit will become zero. The RXCn Flag
can be used to generate a Receive Complete interrupt (see description of the RXCIEn bit).
• Bit 6 – TXCn: USART Transmit Complete n
This flag bit is set when the entire frame in the Transmit Shift Register has been shifted out and
there are no new data currently present in the transmit buffer (UDRn). The TXC Flag bit is auto-
matically cleared when a transmit complete interrupt is executed, or it can be cleared by writing
a one to its bit location. The TXC Flag can generate a Transmit Complete interrupt (see descrip-
tion of the TXCIE bit).
• Bit 5 – UDREn: USART Data Register Empty n
The UDREn Flag indicates if the transmit buffer (UDRn) is ready to receive new data. If UDREn
is one, the buffer is empty, and therefore ready to be written. The UDREn Flag can generate a
Data Register Empty interrupt (see description of the UDRIEn bit).
Bit
(0xC6)
Read/Write
Initial Value
Bit
(0xC0)
Read/Write
Initial Value
RXCn
R/W
7
0
R
7
0
TXCn
R/W
R/W
6
0
6
0
UDREn
R/W
5
0
R
5
1
R/W
4
0
FEn
R
4
0
RXB[7:0]
TXB[7:0]
R/W
DORn
3
0
R
3
0
R/W
UPEn
2
0
R
2
0
R/W
1
0
U2Xn
ATmega169P
R/W
1
0
R/W
MPCMn
0
0
R/W
0
0
UDRn (Read)
UDRn (Write)
UCSRnA
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