Datasheet

Intel
®
Xeon
®
Processor 5500 Series Datasheet, Volume 1 85
Signal Definitions
5 Signal Definitions
5.1 Signal Definitions
Table 5-1. Signal Definitions (Sheet 1 of 4)
Name Type Description Notes
BCLK_DN
BCLK_DP
I Differential bus clock input to the processor.
BCLK_ITP_DN
BCLK_ITP_DP
O Buffered differential bus clock pair to ITP.
BPM#[7:0] I/O BPM#[7:0] are breakpoint and performance monitor signals. They are outputs
from the processor which indicate the status of breakpoints and programmable
counters used for monitoring processor performance. BPM#[7:0] should be
connected in a wired OR topology between all packages on a platform.
CAT_ERR# I/O Indicates that the system has experienced a catastrophic error and cannot
continue to operate. The processor will set this for non-recoverable machine
check errors other internal unrecoverable error. It is expected that every
processor in the system will have this hooked up in a wired-OR configuration.
Since this is an I/O pin, external agents are allowed to assert this pin which will
cause the processor to take a machine check exception.
On Intel Xeon Processor 5500 Series, CAT_ERR# is used for signalling the
following types of errors:
Legacy MCERR’s, CAT_ERR# is pulsed for 16 BCLKs.
Legacy IERR’s, CAT_ERR remains asserted until warm or cold reset.
COMP0 I Impedance Compensation must be terminated on the system board using
precision resistor.
QPI0_CLKRX_DN
QPI0_CLKRX_DP
I
I
Intel® QuickPath Interconnect received clock is the input clock that corresponds
to Intel QuickPath Interconnect port0 received data.
QPI0_CLKTX_DN
QPI0_CLKTX_DP
O
O
Intel QuickPath Interconnect forwarded clock sent with Intel QuickPath
Interconnect port 0 outbound data.
QPI0_COMP I Must be terminated on the system board using precision resistor.
QPI0_DRX_DN[19:0]
QPI0_DRX_DP[19:0]
I
I
QPI0_DRX_DN[19:0] and QPI0_DRX_DP[19:0] comprise the differential receive
data for Intel QuickPath Interconnect port0. The inbound 20 lanes are connected
to another component’s outbound lanes.
QPI0_DTX_DN[19:0]
QPI0_DTX_DP[19:0]
O
O
QPI0_DTX_DN[19:0] and QPI0_DTX_DP[19:0] comprise the differential transmit
data for Intel QuickPath Interconnect port0. The outbound 20 lanes are
connected to another component’s inbound lanes.
QPI1_CLKRX_DN
QPI1_CLKRX_DP
I
I
Intel QuickPath Interconnect received clock is the input clock that corresponds to
Intel QuickPath Interconnect 1 port received data.
QPI1_CLKTX_DN
QPI1_CLKTX_DP
O
O
Intel QuickPath Interconnect forwarded clock sent with Intel QuickPath
Interconnect port1 outbound data.
QPI1_COMP I Must be terminated on the system board using precision resistor.
QPI1_DRX_DN[19:0]
QPI1_DRX_DP[19:0]
I
I
QPI1_DRX_DN[19:0] and QPI1_DRX_DP[19:0] comprise the differential receive
data for Intel QuickPath Interconnect port1. The inbound 20 lanes are connected
to another component’s outbound lanes.
QPI1_DTX_DN[19:0]
QPI1_DTX_DP[19:0]
O
O
QPI1_DTX_DN[19:0] and QPI1_DTX_DP[19:0] comprise the differential transmit
data for Intel QuickPath Interconnect port1. The outbound 20 lanes are
connected to another component’s inbound lanes.
DBR# I DBR# is used only in systems where no debug port is implemented on the
system board. DBR# is used by a debug port interposer so that an in-target
probe can drive system reset.
DDR_COMP[2:0] I Must be terminated on the system board using precision resistors.