MCU AVR 32K FLASH 32TQFP

ATMEGA328P-AU

Manufacturer Part NumberATMEGA328P-AU
DescriptionMCU AVR 32K FLASH 32TQFP
ManufacturerAtmel
SeriesAVR® ATmega
ATMEGA328P-AU datasheets
 

Specifications of ATMEGA328P-AU

Core ProcessorAVRCore Size8-Bit
Speed20MHzConnectivityI²C, SPI, UART/USART
PeripheralsBrown-out Detect/Reset, POR, PWM, WDTNumber Of I /o23
Program Memory Size32KB (16K x 16)Program Memory TypeFLASH
Eeprom Size1K x 8Ram Size2K x 8
Voltage - Supply (vcc/vdd)1.8 V ~ 5.5 VData ConvertersA/D 8x10b
Oscillator TypeInternalOperating Temperature-40°C ~ 85°C
Package / Case32-TQFP, 32-VQFPProcessor SeriesATMEGA32x
CoreAVR8Data Bus Width8 bit
Data Ram Size2 KBInterface Type2-Wire, SPI, USART
Maximum Clock Frequency20 MHzNumber Of Programmable I/os23
Number Of Timers3Maximum Operating Temperature+ 85 C
Mounting StyleSMD/SMT3rd Party Development ToolsEWAVR, EWAVR-BL
Development Tools By SupplierATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKITMinimum Operating Temperature- 40 C
On-chip Adc10 bit, 8 ChannelCpu FamilyATmega
Device CoreAVRDevice Core Size8b
Frequency (max)20MHzTotal Internal Ram Size2KB
# I/os (max)23Number Of Timers - General Purpose3
Operating Supply Voltage (typ)2.5/3.3/5VOperating Supply Voltage (max)5.5V
Operating Supply Voltage (min)1.8VInstruction Set ArchitectureRISC
Operating Temp Range-40C to 85COperating Temperature ClassificationIndustrial
MountingSurface MountPin Count32
Package TypeTQFPController Family/seriesAVR MEGA
No. Of I/o's23Eeprom Memory Size1KB
Ram Memory Size2KBCpu Speed20MHz
Rohs CompliantYesFor Use WithATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVR
Lead Free Status / RoHS StatusLead free / RoHS CompliantOther namesATMEGA328P-20AU
ATMEGA328P-20AU
Q3790246
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Page 209/566

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ATmega48A/48PA/88A/88PA/168A/168PA/328/328
20.6
Data Transfer
Using the USART in MSPI mode requires the Transmitter to be enabled, i.e. the TXENn bit in
the UCSRnB register is set to one. When the Transmitter is enabled, the normal port operation
of the TxDn pin is overridden and given the function as the Transmitter's serial output. Enabling
the receiver is optional and is done by setting the RXENn bit in the UCSRnB register to one.
When the receiver is enabled, the normal pin operation of the RxDn pin is overridden and given
the function as the Receiver's serial input. The XCKn will in both cases be used as the transfer
clock.
After initialization the USART is ready for doing data transfers. A data transfer is initiated by writ-
ing to the UDRn I/O location. This is the case for both sending and receiving data since the
transmitter controls the transfer clock. The data written to UDRn is moved from the transmit buf-
fer to the shift register when the shift register is ready to send a new frame.
Note:
The following code examples show a simple USART in MSPIM mode transfer function based on
polling of the Data Register Empty (UDREn) Flag and the Receive Complete (RXCn) Flag. The
USART has to be initialized before the function can be used. For the assembly code, the data to
be sent is assumed to be stored in Register R16 and the data received will be available in the
same register (R16) after the function returns.
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. The function then waits for data to be present
in the receive buffer by checking the RXCn Flag, before reading the buffer and returning the
value.
8271C–AVR–08/10
To keep the input buffer in sync with the number of data bytes transmitted, the UDRn register must
be read once for each byte transmitted. The input buffer operation is identical to normal USART
mode, i.e. if an overflow occurs the character last received will be lost, not the first data in the buf-
fer. This means that if four bytes are transferred, byte 1 first, then byte 2, 3, and 4, and the UDRn
is not read before all transfers are completed, then byte 3 to be received will be lost, and not byte
1.
209