11. Signals and Pinout
197
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
P1_FRAME#
Tristate bidirectional
PCI-1 Cycle Frame for PCI Bus:
An active low indication from the current bus
master of the beginning and end of a transaction. Driven by the bus master;
sampled by the selected target. Rescinded by the bus master at the end of the
transaction.
P1_GNT[1]# Tristate
bidirectional
PCI-1 Grant:
This is an input when an external arbiter is used and an output
when the internal arbiter is used. As input it is used by the external arbiter to
grant the bus to PowerSpan II. As output it is used by the internal arbiter to grant
the bus to an external master. This pin must be weakly pulled high.
P1_GNT
[4:2]#
Tristate output
PCI-1 Grant:
These are outputs only. They are used by the PCI-1 internal arbiter
to grant the bus to external masters.
PCI_GNT
[7:5]#
Tristate output
PCI-1 Grant:
These outputs may be driven by the PCI-1 or PCI-2 internal arbiter
to grant the bus to external masters. They are assigned to PCI-1 or PCI-2 by
software. These pins should be weakly pulled high in a system.
P1_IDSEL
Input
PCI-1 Initialization Device Select:
Used as a chip select during Configuration
read and write transactions.
P1_INTA#
Bidirectional open
drain
PCI-1 Interrupt A:
An active low level sensitive indication of an interrupt.
Asynchronous to P1_CLK.
P1_IRDY#
Tristate bidirectional
PCI-1 Initiator Ready:
An active low indication of the current bus master’s ability
to complete the current dataphase. Driven by the master; sampled by the
selected target.
P1_PAR
Tristate bidirectional
PCI-1 Parity:
Carries even parity across P1_AD[31:0] and P1_C/BE[3:0]. Driven
by the master for the address and write dataphases. Driven by the target for read
dataphases.
P1_PAR64
Tristate bidirectional
PCI-1 Parity Upper Dword:
Carries even parity across P1_AD[63:32] and
P1_CBE[7:4]. Driven by the master for address and write dataphases. Driven by
the target for read dataphases.
P1_CLK
Input
PCI-1 Clock: Clock input for the PCI-1 Interface:
P1_CLK operates between
25 and 66MHz.
P1_M66EN
Input
PCI-1 66 MHz Enable:
When pulled low, configures the PCI-1 PLL for operation
between 25 and 33 MHz. When pulled high, configures the PCI-1 Interface PLL
for operation above 33 MHz to a maximum of 66 MHz.
P1_PERR#
Tristate bidirectional
PCI-1 Parity Error:
An active low indication of a data parity error. Driven by the
target receiving data. Rescinded by that agent at the end of the transaction.
P1_REQ[1]# Tristate
bidirectional
PCI-1 Bus Request:
This is an output when an external arbiter is used and an
input when the PCI-1 internal arbiter is used. As input it is used by an external
master to request the bus. As output it is used by PowerSpan II to request the
bus. This pin must be weakly pulled high.
P1_REQ[4:2]# Input
PCI-1 Bus Request:
These are inputs only. They can be used by external
masters to request the bus through the PCI-1 arbiter. These pins should be
weakly pulled high in a system.
Table 56: PCI-1 Signals
a
Pin Name
Pin Type
Description