Motorola MPC533 Reference Manual page 350

Bus Operations
9.5.7.3 Bus Busy
BB assertion indicates that the current bus master is using the bus. New masters should not
begin transfer until this signal is negated. The bus owner should not relinquish or negate
this signal until the transfer is complete. To avoid contention on the BB line, the master
should three-state this signal when it gets a logical one value. This requires the connection
of an external pull-up resistor to ensure that a master that acquires the bus is able to
recognize the BB line negated, regardless of how many cycles have passed since the
previous master relinquished the bus. Refer to Figure 9-25.
MPC5xx Device
(Slave 1)
Figure 9-25. Master Signals Basic Connection
9-34
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
External Bus
TS
BB
Slave 2
MPC533 Reference Manual
Master
MOTOROLA