ATMEGA645V-8AU Atmel, ATMEGA645V-8AU Datasheet - Page 168

• Manufacturer Part Number: ATMEGA645V-8AU
• Description: IC AVR MCU FLASH 64K 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA645V-8AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K 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: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, UART, USI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Controller Family/series: AVR MEGA
• No. Of I/o's: 54
• Eeprom Memory Size: 2KB
• Ram Memory Size: 4KB
• Cpu Speed: 8MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• Data Rom Size: 2 KB
• Height: 1 mm
• Length: 14 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Width: 14 mm
• 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 SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.7.2
2570M–AVR–04/11
Receiving Frames with 9 Data Bits
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.
If 9-bit characters are used (UCSZ=7) the ninth bit must be read from the RXB8n bit in UCSRnB
before reading the low bits from the UDRn. This rule applies to the FEn, DORn and UPEn Sta-
tus Flags as well. Read status from UCSRnA, then data from UDRn. Reading the UDRn I/O
location will change the state of the receive buffer FIFO and consequently the TXB8n, FEn,
DORn and UPEn bits, which all are stored in the FIFO, will change.
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
r16, UDR0
;
“About Code Examples” on page
(1)
(1)
ATmega325/3250/645/6450
9.
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