SB4002A_Data Sheet_EN

SB4002A
38
In the above figure, FRAME# is asserted at CLK 2 and the address phase is started. As LOCK# is
asserted, if the PCI command is Memory Read, the exclusive access request transaction is
executed. As LOCK# is asserted at CLK 3 and the data phase is terminated normally at CLK 4, an
exclusive access is started.
TRDY#
ADDRESS
Continue
LOCK#
DEVSEL#
AD
IRDY#
FRAME#
Release
3
DATA
5
CLK
21 4
Figure 2-10. Continuing or Releasing Exclusive Access
The above figure shows the state that an exclusive access has been already started. The figure
shows the transaction that the master that started the exclusive access accesses the target as
LOCK# is deasserted at CLK 2. At CLK 3, LOCK# is asserted for the transaction. At CLK4, data
transfer occurs and the transaction is terminated. The exclusive access continues if LOCK# is kept
asserted, or is released if LOCK# is deasserted.