Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
993
Clocking and Reset—Intel
®
81341 and 81342
19.2
Reset Overview
19.2.1
Fundamental Reset
There are four fundamental (hardware) resets for the 81341 and 81342. The main
power on reset is controlled through the PCI reset signal (
P_RST#
). When this signal is
asserted, the entire I/O Processor is placed in a reset state. The other resets have
differing behavior based on strapping options and chip mode. The reset straps are
sampled at the exit of all fundamental resets.
•
P_RST#
— This is an asynchronous input pin which resets the entire chip. All reset
straps are sampled at the rising edge of P_RST#.
•
WARM_RST#
— This is an asynchronous input pin which resets the entire chip
with the exception of ‘sticky’ bits in the PMMR registers. All reset straps are
sampled at the rising edge of WARM_RST#.
•
PCI Express Hot Reset —
When operating as an endpoint and the Hot Reset
sequence is received in the TS1 ordered set, the entire chip is reset with the
exception of the PCI Express physical layer and ‘sticky’ bits in the PMMR registers.
This reset is not applicable when the PCI Express interface is disabled. A subset of
straps are sampled as described in
Section 19.5, “Reset Strapping Options”
•
PCI Express Loopback
— When operating as an endpoint and the Loopback
sequence is received in the TS1 ordered set, the entire chip is reset with the
exception of the PCI Express physical layer and “sticky” bits in the PMMR registers.
This reset is not applicable when the PCI Express interface is disabled. A subset of
straps are sampled as described in
Section 19.5, “Reset Strapping Options”
•
PCI Express Disable Link —
When operating as an endpoint and the Disable Link
sequence is received in the TS1 ordered set, the entire chip is reset with the
exception of the PCI Express physical layer and “sticky” bits in the PMMR registers.
This reset is not applicable when the PCI Express interface is disabled. A subset of
straps are sampled as described in
Section 19.5, “Reset Strapping Options”
•
PCI Express Link Down
— When operating as an endpoint and the PCI Express*
Link transitions to the link down state, the entire chip, including the PCI Express*
physically layer, is reset with the exception of “sticky” bits in the PMMR registers.
This reset is not applicable when the PCI Express* interface is disabled. A subset of