ATMEGA8515-16AU Atmel, ATMEGA8515-16AU Datasheet - Page 148

• Manufacturer Part Number: ATMEGA8515-16AU
• Description: IC AVR MCU 8K 16MHZ 5V 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8515-16AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 16MHz
• Interface Type: SPI/USART
• Total Internal Ram Size: 512Byte
• # I/os (max): 35
• Number Of Timers - General Purpose: 2
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4.5V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Package Type: TQFP
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 35
• Number Of Timers: 2
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Package: 44TQFP
• Family Name: ATmega
• Maximum Speed: 16 MHz
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - 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 SYSTEMATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Compliant

Parity Checker
Disabling the Receiver
Flushing the Receive Buffer
Asynchronous Data
Reception
148
ATmega8515(L)
The Parity Checker is active when the high USART Parity mode (UPM1) bit is set. Type
of parity check to be performed (odd or even) is selected by the UPM0 bit. When
enabled, the parity checker calculates the parity of the data bits in incoming frames and
compares the result with the parity bit from the serial frame. The result of the check is
stored in the receive buffer together with the received data and stop bits. The Parity
Error (PE) Flag can then be read by software to check if the frame had a parity error.
The PE bit is set if the next character that can be read from the receive buffer had a par-
ity error when received and the parity checking was enabled at that point (UPM1 = 1).
This bit is valid until the receive buffer (UDR) is read.
In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from
ongoing receptions will therefore be lost. When disabled (i.e., the RXEN is set to zero)
the Receiver will no longer override the normal function of the RxD port pin. The
Receiver buffer FIFO will be flushed when the Receiver is disabled. Remaining data in
the buffer will be lost
The Receiver buffer FIFO will be flushed when the Receiver is disabled (i.e., the buffer
will be emptied of its contents). Unread data will be lost. If the buffer has to be flushed
during normal operation, due to for instance an error condition, read the UDR I/O loca-
tion until the RXC Flag is cleared. The following code example shows how to flush the
receive buffer.
Note:
The USART includes a clock recovery and a data recovery unit for handling asynchro-
nous data reception. The clock recovery logic is used for synchronizing the internally
generated baud rate clock to the incoming asynchronous serial frames at the RxD pin.
The data recovery logic samples and low pass filters each incoming bit, thereby improv-
ing the noise immunity of the Receiver. The asynchronous reception operational range
depends on the accuracy of the internal baud rate clock, the rate of the incoming
frames, and the frame size in number of bits.
Assembly Code Example
C Code Example
USART_Flush:
void USART_Flush( void )
{
}
sbis UCSRA, RXC
ret
in
rjmp USART_Flush
unsigned char dummy;
while ( UCSRA & (1<<RXC) ) dummy = UDR;
1. See “About Code Examples” on page 7.
r16, UDR
(1)
(1)
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