Arbitration - Fujitsu MB86R02 Jade-D Hardware Manual

Graphics controller

Hide thumbs Also See for MB86R02 Jade-D:

Table of Contents

MB86R02 'Jade-D' Hardware Manual V1.64

29.8.5 Arbitration

Arbitration occurs when other masters attempt to transmit data at the same time.

• If a units own transfer data is "1" and the data on the SDA line is "0", AL = "1" is set and

arbitration is lost.

• If a start condition is attempted while other masters are using the bus, AL = "1" is set and

arbitration is lost.

• If the other masters' start condition is detected before a start condition occurs although an

unused bus is confirmed and MSS = "1" is set, then AL = "1" is set and arbitration is lost.

If the AL bit is set to "1", the status becomes MSS = "0" and TRX = "0" and the state changes to slave

reception mode. If arbitration is lost (the right to use the bus is lost), the master discontinues to drive the

SDA line. However, driving the SCL line is not discontinued until 1 byte of the transmission ends and the

interrupt is cleared.

Since input and output are

matched, right to use bus is acquired.

Since input and output are

unmatched, right to use bus is lost.