PM7384 FREEDM-84P672
DATA SHEET
PMC-1990445
ISSUE 5
FRAME ENGINE AND DATA LINK MANAGER 84P672
Pin Name Type
Pin
Function
No.
STOPB
I/O
U25
The active low stop signal (STOPB) requests
the initiator to stop the current bus transaction.
When STOPB is set high by a target, the
initiator continues with the transaction. When
STOPB is set low, the initiator will stop the
current transaction.
When the FREEDM-84P672 is the initiator,
STOPB is an input. When STOPB is sampled
low, the FREEDM-84P672 will terminate the
current transaction in the next PCICLK cycle.
When the FREEDM-84P672 is the target,
STOPB is an output. The FREEDM-84P672
only issues transaction stop requests when
responding to reads and writes to configuration
space (disconnecting after 1 DWORD
transferred) or if an initiator introduces wait
states during a transaction.
When the FREEDM-84P672 is not involved in
the current transaction, STOPB is tristated.
STOPB 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.
IDSEL
Input
M24
The initialization device select signal (IDSEL)
enables read and write access to the PCI
configuration registers. When IDSEL is set high
during the address phase of a transaction and
the C/BEB[3:0] code indicates a register read or
write, the FREEDM-84P672 performs a PCI
configuration register transaction and asserts
the DEVSELB signal in the next PCICLK period.
IDSEL is sampled on the rising edge of
PCICLK.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
23
PMC [ PMC-SIERRA, INC ]
