ATmega329A Atmel Corporation, ATmega329A Datasheet - Page 204

• Manufacturer Part Number: ATmega329A
• Manufacturer: Atmel Corporation

Specifications of ATmega329A

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 100
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

21. USI – Universal Serial Interface
21.1
21.2
8284D–AVR–6/11
Features
Overview
ATmega169A/PA/329A/PA/3290A/PA/649A/P/6490A/P
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The Universal Serial Interface, or USI, provides the basic hardware resources needed for serial
communication. Combined with a minimum of control software, the USI allows significantly
higher transfer rates and uses less code space than solutions based on software only. Interrupts
are included to minimize the processor load.
A simplified block diagram of the USI is shown in
ment of I/O pins, refer to
including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit loca-
tions are listed in the
Figure 21-1. Universal Serial Interface, Block Diagram
The 8-bit Shift Register is directly accessible via the data bus and contains the incoming and
outgoing data. The register has no buffering so the data must be read as quickly as possible to
ensure that no data is lost. The most significant bit is connected to one of two output pins
depending of the wire mode configuration. A transparent latch is inserted between the Serial
Register Output and output pin, which delays the change of data output to the opposite clock
edge of the data input sampling. The serial input is always sampled from the Data Input (DI) pin
independent of the configuration.
Two-wire Synchronous Data Transfer (Master or Slave)
Three-wire Synchronous Data Transfer (Master or Slave)
Data Received Interrupt
Wake up from Idle Mode
In Two-wire Mode: Wake-up from All Sleep Modes, Including Power-down Mode
Two-wire Start Condition Detector with Interrupt Capability
USIDR
USICR
USISR
”Register Description” on page
2
4-bit Counter
”Pin Configurations” on page
3
2
1
0
3
2
1
0
D Q
LE
[1]
Figure 21-1 on page 204
TIM0 COMP
0
1
212.
Two-wire Clock
Control Unit
2. CPU accessible I/O Registers,
CLOCK
HOLD
DO
DI/SDA
USCK/SCL
For the actual place-
(Output only)
(Input/Open Drain)
(Input/Open Drain)
204