ATmega256RZAV Atmel Corporation, ATmega256RZAV Datasheet - Page 215

• Manufacturer Part Number: ATmega256RZAV
• Manufacturer: Atmel Corporation

Specifications of ATmega256RZAV

• Flash (kbytes): 256 Kbytes
• Max. Operating Frequency: 16 MHz
• Max I/o Pins: 54
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Crypto Engine: No
• Sram (kbytes): 8
• Eeprom (bytes): 4096
• Operating Voltage (vcc): 1.8 to 3.6
• Timers: 6
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 0.25
• Antenna Diversity: No
• External Pa Control: No
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -101
• Receive Current Consumption (ma): 16.0
• Transmit Current Consumption (ma): 17.0
• Link Budget (dbm): 104

22.6.2
2549N–AVR–05/11
Receiving Frames with 9 Data Bits
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 (UCSZn=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 Status 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.
The following code example shows a simple USART receive function that handles both nine bit
characters and the status bits.
Assembly Code Example
C Code Example
USART_Receive:
unsigned char USART_Receive( void )
{
}
; Wait for data to be received
lds
sbrs r17, RXCn
rjmp USART_Receive
; Get and return received data from buffer
lds
ret
/* Wait for data to be received */
while ( !(UCSRnA & (1<<RXCn)) )
/* Get and return received data from buffer */
return UDRn;
1.
See “About Code Examples” on page 11.
r17, UCSRnA
r16, UDRn
;
(1)
(1)
ATmega640/1280/1281/2560/2561
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