ATmega48PA Automotive Atmel Corporation, ATmega48PA Automotive Datasheet - Page 218
ATmega48PA Automotive
Manufacturer Part Number
ATmega48PA Automotive
Description
Manufacturer
Atmel Corporation
- Current page: 218 of 371
- Download datasheet (12Mb)
218
Atmel ATmega48PA/88PA/168PA [Preliminary]
Arbitration is carried out by all masters continuously monitoring the SDA line after outputting
data. If the value read from the SDA line does not match the value the Master had output, it
has lost the arbitration. Note that a Master can only lose arbitration when it outputs a high SDA
value while another Master outputs a low value. The losing Master should immediately go to
Slave mode, checking if it is being addressed by the winning Master. The SDA line should be
left high, but losing masters are allowed to generate a clock signal until the end of the current
data or address packet. Arbitration will continue until only one Master remains, and this may
take many bits. If several masters are trying to address the same Slave, arbitration will con-
tinue into the data packet.
Figure 22-8. 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 compo-
sition 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.
Synchronized
SCL Line
SDA from
SDA from
Master A
Master B
SDA Line
START
Arbitration, SDA
Master A Loses
A
SDA
9223B–AVR–09/11
Related parts for ATmega48PA Automotive
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MCU AVR 4K ISP FLASH 20MHZ 32QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
MCU AVR 4K ISP FLSH 20MHZ 32TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 4K ISP FLASH 20MHZ 28DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 4K FLASH 20MHZ 32TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 4K FLASH 20MHZ 32QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 4K FLASH 20MHZ 28-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 4K FLASH 20MHZ 28QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet: