ATMEGA8L-8MJ Atmel, ATMEGA8L-8MJ Datasheet - Page 140

• Manufacturer Part Number: ATMEGA8L-8MJ
• Description: IC MCU AVR 8K 5V 8MHZ 32-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8L-8MJ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

140
ATmega8(L)
The following code example shows a simple USART receive function that handles both 9-bit
characters and the status bits.
Note:
The receive function example reads all the I/O Registers into the Register File before any com-
putation is done. This gives an optimal receive buffer utilization since the buffer location read will
be free to accept new data as early as possible.
Assembly Code Example
C Code Example
USART_Receive:
USART_ReceiveNoError:
unsigned int USART_Receive( void )
{
}
; Wait for data to be received
sbis UCSRA, RXC
rjmp USART_Receive
; Get status and ninth bit, then data from buffer
in
in
in
; If error, return -1
andi r18,(1<<FE)|(1<<DOR)|(1<<PE)
breq USART_ReceiveNoError
ldi
ldi
; Filter the ninth bit, then return
lsr
andi r17, 0x01
ret
unsigned char status, resh, resl;
/* Wait for data to be received */
while ( !(UCSRA & (1<<RXC)) )
/* Get status and ninth bit, then data */
/* from buffer */
status = UCSRA;
resh = UCSRB;
resl = UDR;
/* If error, return -1 */
if ( status & (1<<FE)|(1<<DOR)|(1<<PE) )
/* Filter the ninth bit, then return */
resh = (resh >> 1) & 0x01;
return ((resh << 8) | resl);
1. See
return -1;
r18, UCSRA
r17, UCSRB
r16, UDR
r17, HIGH(-1)
r16, LOW(-1)
r17
;
“About Code Examples” on page 8
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2486Z–AVR–02/11