IDT 89HPES24N3A, User Manual

Page: 153 / 168

IDT Configuration Registers
PES24N3A User Manual 9 - 59 April 10, 2008
Notes
GPESTS - General Purpose Event Status (0x454)
UARBTC - U-Bus Arbiter Transfer Count (0x458)
2 P2GPEE RW 0x0
Sticky
Port 2 General Purpose Event Enable. When this bit is
set, the hot-plug INTx, MSI and PME event notification
mechanisms defined by the PCIe base 1.1 specification are
disabled for port 2 and are instead signalled through Gen-
eral Purpose Event (GPEN) signal assertions. GPEN is an
alternate function of GPIO[7].
3 Reserved RO 0x0 Reserved field.
4 P4GPEE RW 0x0
Sticky
Port 4 General Purpose Event Enable. When this bit is
set, the hot-plug INTx, MSI and PME event notification
mechanisms defined by the PCIe base 1.1 specification are
disabled for port 4 and are instead signalled through Gen-
eral Purpose Event (GPEN) signal assertions. GPEN is an
alternate function of GPIO[7].
31:3 Reserved RO 0x0 Reserved field.
Bit
Field
Field
Name
Type
Default
Value
Description
1:0 Reserved RO 0x0 Reserved field.
2 P2GPES RO 0x0 Port 2 General Purpose Event Status. When this bit is set,
the corresponding port is signalling a general purpose event
by asserting the GPEN signal. This bit is never set if the cor-
responding general purpose event is not enabled in the
GPECTL register.
GPEN is an alternate function of GPIO[7] and GPIO[7] is
asserted only if enabled to operate as an alternate function.
3 Reserved RO 0x0 Reserved field.
4 P4GPES RO 0x0 Port 4 General Purpose Event Status. When this bit is set,
the corresponding port is signalling a general purpose event
by asserting the GPEN signal. This bit is never set if the cor-
responding general purpose event is not enabled in the
GPECTL register. GPEN is an alternate function of GPIO[7]
and GPIO[7] is asserted only if enabled to operate as an
alternate function.
31:5 Reserved RO 0x0 Reserved field.
Bit
Field
Field
Name
Type
Default
Value
Description
7:0 D2UTC RW 0x01
Sticky
Downstream to Upstream Transfer Count. This field con-
tains the downstream to upstream transfer count. The
D2UCTC field in the UARBCTC register is set to this value
after each arbitration period.
15:8 P2PTC RW 0x01
Sticky
Peer to Peer Transfer Count. This field contains the peer
to peer transfer count. The P2PCTC field in the UARBCTC
register is set to this value after each arbitration period.
Bit
Field
Field
Name
Type
Default
Value
Description