![](http://datasheet.mmic.net.cn/330000/PM7382-PI_datasheet_16444416/PM7382-PI_38.png)
RELEASED
DATA SHEET
PM7382 FREEDM-32P256
ISSUE 3
PMC-2010333
FRAME ENGINE AND DATA LINK MANAGER 32P256
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA,INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
27
Pin Name Type
Pin
No.
Function
DEVSELB I/O
R2
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-32P256 is the initiator,
DEVSELB is an input. If no target responds to
an address in six PCICLK cycles, the FREEDM-
32P256 will abort the current transaction and
alerts the PCI Host via an interrupt.
When the FREEDM-32P256 is the target,
DEVSELB is an output. DELSELB is set low
when the address on AD[31:0] is recognised.
When the FREEDM-32P256 is not involved in
the current transaction, DEVSELB is tristated.
FREEDM-32P256 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
R1
The active low bus lock signal (LOCKB) locks a
target device. When LOCKB and FRAME are
set low, and the FREEDM-32P256 is the target,
an initiator is locking the FREEDM-32P256 as an
"owned" target. Under these circumstances, the
FREEDM-32P256 will reject all transaction with
other initiators. The FREEDM-32P256 will
continue to reject other initiators until its owner
releases the lock by forcing both FRAMEB and
LOCKB high. As a initiator, the FREEDM-
32P256 will never lock a target.
LOCKB is sampled using the rising edge of
PCICLK.