PM7384 FREEDM-84P672
DATA SHEET
PMC-1990445
ISSUE 5
FRAME ENGINE AND DATA LINK MANAGER 84P672
Pin Name Type
DEVSELB I/O
Pin
Function
No.
T24
The active low device select signal (DEVSELB)
indicates that a target claims the current bus
transaction. During the address phase of a
transaction, all targets decode the address on
the AD[31:0] bus. When a target, recognizes
the address as its own, it sets DEVSELB low to
indicate to the initiator that the address is valid.
If no target claims the address in six bus clock
cycles, the initiator assumes that the target
does not exist or cannot respond and aborts the
transaction.
When the FREEDM-84P672 is the initiator,
DEVSELB is an input. If no target responds to
an address in six PCICLK cycles, the FREEDM-
84P672 will abort the current transaction and
alerts the PCI Host via an interrupt.
When the FREEDM-84P672 is the target,
DEVSELB is an output. DELSELB is set low
when the address on AD[31:0] is recognised.
When the FREEDM-84P672 is not involved in
the current transaction, DEVSELB is tristated.
FREEDM-84P672 is updated on the rising edge
of PCICLK or sampled on the rising edge of
PCICLK depending on whether it is an output or
an input.
LOCKB
Input
T23
The active low bus lock signal (LOCKB) locks a
target device. When LOCKB and FRAME are
set low, and the FREEDM-84P672 is the target,
an initiator is locking the FREEDM-84P672 as
an "owned" target. Under these circumstances,
the FREEDM-84P672 will reject all transaction
with other initiators. The FREEDM-84P672 will
continue to reject other initiators until its owner
releases the lock by forcing both FRAMEB and
LOCKB high. As a initiator, the FREEDM-
84P672 will never lock a target.
LOCKB is sampled using the rising edge of
PCICLK.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
24
PMC [ PMC-SIERRA, INC ]
