ATA6603-EK Atmel, ATA6603-EK Datasheet - Page 200

• Manufacturer Part Number: ATA6603-EK
• Description: MCU, MPU & DSP Development Tools Demoboard LIN-MCM
• Manufacturer: Atmel

Specifications of ATA6603-EK

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.17.5.2
200
ATA6602/ATA6603
Sending Frames with 9 Data Bit
If 9-bit characters are used (UCSZn = 7), the ninth bit must be written to the TXB8 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 UCSRnA,UDREn
rjmp USART_Transmit
; Copy 9th bit from r17 to TXB8
cbi
sbrc r17,0
sbi
; Put LSB data (r16) into buffer, sends the data
out
ret
/* Wait for empty transmit buffer */
while ( !( UCSRnA & (1<<UDREn))) )
/* Copy 9th bit to TXB8 */
UCSRnB &= ~(1<<TXB8);
if ( data & 0x0100 )
/* Put data into buffer, sends the data */
UDRn = data;
1. These transmit functions are written to be general functions. They can be optimized if the con-
2. The example code assumes that the part specific header file is included.
UCSRnB |= (1<<TXB8);
tents of the UCSRnB is static. For example, only the TXB8 bit of the UCSRnB Register is used
after initialization.
For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI”
instructions must be replaced with instructions that allow access to extended I/O. Typically
“LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”.
UCSRnB,TXB8
UCSRnB,TXB8
UDRn,r16
;
(1)(2)
(1)(2)
4921E–AUTO–09/09