Table 2−8. PCI Interface Control Terminals
Internal pullup/pulldown resistors and pin strapping are not applicable for the PCI interface control terminals.
TERMINAL
I/O
TYPE
POWER
RAIL
EXTERNAL
COMPONENTS
DESCRIPTION
INPUT OUTPUT
NAME
NO.
PCI device select. The controller asserts DEVSEL to claim a PCI cycle
as the target device. As a PCI initiator on the bus, the controller monitors
DEVSEL until a target responds. If no target responds before timeout
occurs, then the controller terminates the cycle with an initiator abort.
Pullup resistor per
PCI specification
N08
V07
T02
I/O
I/O
PCII3
PCII3
PCIO3
PCIO3
V
DEVSEL
CCP
PCI cycle frame. FRAME is driven by the initiator of a bus cycle. FRAME
is asserted to indicate that a bus transaction is beginning, and data
transfers continue while this signal is asserted. When FRAME is
deasserted, the PCI bus transaction is in the final data phase.
Pullup resistor per
PCI specification
V
FRAME
CCP
PCI bus grant. GNT is driven by the PCI bus arbiter to grant the
controller access to the PCI bus after the current data transaction has
completed. GNT may or may not follow a PCI bus request, depending on
the PCI bus parking algorithm.
I
I
PCII3
PCII3
V
V
GNT
CCP
Initialization device select. IDSEL selects the controller during
W05 configuration space accesses. IDSEL can be connected to one of the
upper 24 PCI address lines on the PCI bus.
IDSEL
CCP
PCI initiator ready. IRDY indicates the ability of the PCI bus initiator to
complete the current data phase of the transaction. A data phase is
completed on a rising edge of PCLK where both IRDY and TRDY are
asserted. Until IRDY and TRDY are both sampled asserted, wait states
are inserted.
Pullup resistor per
PCI specification
U07
I/O
PCII3
PCII3
PCIO3
V
IRDY
CCP
PCI parity error indicator. PERR is driven by a PCI controller to indicate
that calculated parity does not match PAR when PERR is enabled
through bit 6 of the command register (PCI offset 04h, see Section 4.4).
Pullup resistor per
PCI specification
V08
U01
I/O
O
PCIO3
PCIO3
V
V
PERR
REQ
CCP
PCI bus request. REQ is asserted by the controller to request access to
the PCI bus as an initiator.
CCP
PCI system error. SERR is an output that is pulsed from the controller
when enabled through bit 8 of the command register (PCI offset 04h,
see Section 4.4) indicating a system error has occurred. The controller
need not be the target of the PCI cycle to assert this signal. When SERR
is enabled in the command register, this signal also pulses, indicating
that an address parity error has occurred on a CardBus interface.
Pullup resistor per
PCI specification
U08
O
PCIO3
V
SERR
CCP
PCI cycle stop signal. STOP is driven by a PCI target to request the
initiator to stop the current PCI bus transaction. STOP is used for target
disconnects and is commonly asserted by target devices that do not
support burst data transfers.
Pullup resistor per
PCI specification
W08
R08
I/O
I/O
PCII3
PCII3
PCIO3
PCIO3
V
V
STOP
TRDY
CCP
PCI target ready. TRDY indicates the ability of the primary bus target to
complete the current data phase of the transaction. A data phase is
completed on a rising edge of PCLK when both IRDY and TRDY are
asserted. Until both IRDY and TRDY are asserted, wait states are
inserted.
Pullup resistor per
PCI specification
CCP
2−17
TI [ TEXAS INSTRUMENTS ]
