ATMEGA164PA-AU Atmel, ATMEGA164PA-AU Datasheet - Page 204

• Manufacturer Part Number: ATMEGA164PA-AU
• Description: MCU AVR 16KB FLASH 20MHZ 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA164PA-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• 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): 20MHz
• Interface Type: 2-Wire/SPI/USART
• Total Internal Ram Size: 1KB
• # I/os (max): 32
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 2.5/3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 1.8V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Package Type: TQFP
• Package: 44TQFP
• Family Name: ATmega
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 2.5|3.3|5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.6.1
19.6.2
19.7
8272A–AVR–01/10
AVR USART MSPIM vs. AVR SPI
Transmitter and Receiver Flags and Interrupts
Disabling the Transmitter or Receiver
The RXCn, TXCn, and UDREn flags and corresponding interrupts in USART in MSPIM mode
are identical in function to the normal USART operation. However, the receiver error status flags
(FE, DOR, and PE) are not in use and is always read as zero.
The disabling of the transmitter or receiver in USART in MSPIM mode is identical in function to
the normal USART operation.
The USART in MSPIM mode is fully compatible with the AVR SPI regarding:
• Master mode timing diagram.
• The UCPOLn bit functionality is identical to the SPI CPOL bit.
• The UCPHAn bit functionality is identical to the SPI CPHA bit.
• The UDORDn bit functionality is identical to the SPI DORD bit.
However, since the USART in MSPIM mode reuses the USART resources, the use of the
USART in MSPIM mode is somewhat different compared to the SPI. In addition to differences of
the control register bits, and that only master operation is supported by the USART in MSPIM
mode, the following features differ between the two modules:
• The USART in MSPIM mode includes (double) buffering of the transmitter. The SPI has no
• The USART in MSPIM mode receiver includes an additional buffer level.
• The SPI WCOL (Write Collision) bit is not included in USART in MSPIM mode.
• The SPI double speed mode (SPI2X) bit is not included. However, the same effect is achieved
• Interrupt timing is not compatible.
• Pin control differs due to the master only operation of the USART in MSPIM mode.
A comparison of the USART in MSPIM mode and the SPI pins is shown in
204.
Table 19-3.
164A/164PA/324A/324PA/644A/644PA/1284/1284P
buffer.
by setting UBRRn accordingly.
USART_MSPIM
XCKn
RxDn
TxDn
(N/A)
Comparison of USART in MSPIM mode and SPI pins.
MOSI
MISO
SCK
SPI
SS
Comment
Master Out only
Master In only
Not supported by USART in MSPIM
(Functionally identical)
Table 19-3 on page
204