ATMEGA88PA-CCU Atmel, ATMEGA88PA-CCU Datasheet - Page 221

• Manufacturer Part Number: ATMEGA88PA-CCU
• Description: IC MCU AVR 8K FLASH 32VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA88PA-CCU

• 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: 23
• Program Memory Size: 8KB (4K 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: 32-VFQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8271C–AVR–08/10
Figure 21-8. Arbitration Between Two Masters
Note that arbitration is not allowed between:
• A REPEATED START condition and a data bit.
• A STOP condition and a data bit.
• A REPEATED START and a STOP condition.
It is the user software’s responsibility to ensure that these illegal arbitration conditions never
occur. This implies that in multi-master systems, all data transfers must use the same composi-
tion of SLA+R/W and data packets. In other words: All transmissions must contain the same
number of data packets, otherwise the result of the arbitration is undefined.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
Synchronized
SCL Line
SDA from
SDA from
Master A
Master B
SDA Line
START
Arbitration, SDA
Master A Loses
A
SDA
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