ATMEGA329P-20MN Atmel, ATMEGA329P-20MN Datasheet - Page 163

• Manufacturer Part Number: ATMEGA329P-20MN
• Description: IC MCU AVR 32K 20MHZ 64QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA329P-20MN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• 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): 2.7 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: Lead free / RoHS Compliant

8021G–AVR–03/11
The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. E.g. if MOSI is placed on pin PB5, replace DD_MOSI with DDB5 and DDR_SPI with DDRB.
Note:
Assembly Code Example
C Code Example
SPI_MasterInit:
SPI_MasterTransmit:
Wait_Transmit:
void SPI_MasterInit(void)
{
}
void SPI_MasterTransmit(char cData)
{
}
; Set MOSI and SCK output, all others input
ldi
out
; Enable SPI, Master, set clock rate fck/16
ldi
out
ret
; Start transmission of data (r16)
out
; Wait for transmission complete
sbis SPSR,SPIF
rjmp Wait_Transmit
ret
/* Set MOSI and SCK output, all others input */
DDR_SPI = (1<<DD_MOSI)|(1<<DD_SCK);
/* Enable SPI, Master, set clock rate fck/16 */
SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);
/* Start transmission */
SPDR = cData;
/* Wait for transmission complete */
while(!(SPSR & (1<<SPIF)))
1.
;
See Section “5.” on page 9.
r17,(1<<DD_MOSI)|(1<<DD_SCK)
DDR_SPI,r17
r17,(1<<SPE)|(1<<MSTR)|(1<<SPR0)
SPCR,r17
SPDR,r16
(1)
(1)
ATmega329P/3290P
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