ATMEGA329V-8MI Atmel, ATMEGA329V-8MI Datasheet - Page 176

• Manufacturer Part Number: ATMEGA329V-8MI
• Description: IC AVR MCU 32K 8MHZ 64-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA329V-8MI

• 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: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K 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-MLF®, 64-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

19.6.2
176
ATmega329/3290/649/6490
Sending Frames with 9 Data Bit
The function simply waits for the transmit buffer to be empty by checking the UDREn Flag,
before loading it with new data to be transmitted. If the Data Register Empty interrupt is utilized,
the interrupt routine writes the data into the buffer.
If 9-bit characters are used (UCSZ = 7), the ninth bit must be written to the TXB8n bit in
UCSRnB before the low byte of the character is written to UDRn. The following code examples
show a transmit function that handles 9-bit characters. For the assembly code, the data to be
sent is assumed to be stored in registers R17:R16.
Notes:
The ninth bit can be used for indicating an address frame when using multi processor communi-
cation mode or for other protocol handling as for example synchronization.
Assembly Code Example
C Code Example
USART_Transmit:
void USART_Transmit( unsigned int data )
{
}
; Wait for empty transmit buffer
sbis UCSR0A,UDRE0
rjmp USART_Transmit
; Copy 9th bit from r17 to TXB80
cbi
sbrc r17,0
sbi
; Put LSB data (r16) into buffer, sends the data
out
ret
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0))) )
/* Copy 9th bit to TXB80 */
UCSR0B &= ~(1<<TXB80);
if ( data & 0x0100 )
/* Put data into buffer, sends the data */
UDR0 = data;
1. These transmit functions are written to be general functions. They can be optimized if the con-
2.
UCSR0B |= (1<<TXB80);
tents of the UCSRnB is static. For example, only the TXB80 bit of the UCSRnB Register is
used after initialization.
See “About Code Examples” on page 9.
UCSR0B,TXB80
UCSR0B,TXB80
UDR0,r16
;
(1)(2)
(1)(2)
2552K–AVR–04/11