Atmel ATmega328P Xplained Mini MEGA328P-XMINI MEGA328P-XMINI Data Sheet
Product codes
MEGA328P-XMINI
207
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
22.
2-wire Serial Interface
22.1
Features
•
Simple Yet Powerful and Flexible Communication Interface, only two Bus Lines Needed
•
Both Master and Slave Operation Supported
•
Device can Operate as Transmitter or Receiver
•
7-bit Address Space Allows up to 128 Different Slave Addresses
•
Multi-master Arbitration Support
•
Up to 400kHz Data Transfer Speed
•
Slew-rate Limited Output Drivers
•
Noise Suppression Circuitry Rejects Spikes on Bus Lines
•
Fully Programmable Slave Address with General Call Support
•
Address Recognition Causes Wake-up When AVR is in Sleep Mode
•
Compatible with Philips’ I
2
C protocol
22.2
2-wire Serial Interface Bus Definition
The 2-wire Serial Interface (TWI) is ideally suited for typical microcontroller applications. The TWI protocol
allows the systems designer to interconnect up to 128 different devices using only two bi-directional bus lines,
one for clock (SCL) and one for data (SDA). The only external hardware needed to implement the bus is a single
pull-up resistor for each of the TWI bus lines. All devices connected to the bus have individual addresses, and
mechanisms for resolving bus contention are inherent in the TWI protocol.
allows the systems designer to interconnect up to 128 different devices using only two bi-directional bus lines,
one for clock (SCL) and one for data (SDA). The only external hardware needed to implement the bus is a single
pull-up resistor for each of the TWI bus lines. All devices connected to the bus have individual addresses, and
mechanisms for resolving bus contention are inherent in the TWI protocol.
Figure 22-1.
TWI Bus Interconnection
Device 1
Device 2
Device 3
Device n
SDA
SCL
........
R1
R2
V
CC