Specifications

Baseboard Connectors
007-4276-001 123
* Signal is active low.
** Pins are numbered with respect to the module edge connector. Axx signals appear on
the front (processor side) of the processor card.
***Signals that have no connection except for a pull-up resistor to 2.5 V are labeled with
the signal mnemonic followed by “(pu).”
Processor Termination, Regulation, and Power
The termination circuitry required by the Intel Pentium III Xeon processor bus (AGTL+)
signaling environment and the circuitry to set the AGTL+ reference voltage are
implemented directly on the processor cards. The baseboard provides 1.5 V AGTL+
termination power (VTT), and VRM 8.3-compliant DC-to-DC converters to provide
processor power (VCCP) at each connector.
The baseboard provides four embedded VRMs and three VRM sockets to power the
processors, which derive power from the 5 V and 12 V supplies. Each processor has a
separate VRM to power its core; however, two processors share a VRM to power their
cache.
Table A-26 shows the cable pinout assignments for the three VRM connectors.
A082 TEST_VTT (pu) B082 VCCP A165 PWR_EN0 B165 RESERVED (nc)
A083 RESERVED (nc) B083 RESERVED (nc)
Table A-26 Processor VRM Connectors (J2A2, J2B1, J2C1)
Pin Signal Type*
A1 P5VIN1 POWER
A2 P5VIN2 POWER
A3 P5VIN3 POWER
A4 P12VIN1 POWER
Table A-25 (continued) Processor Card Connector (J7A1, J7B1, J7C1, J7D1)
Pin** Signal Pin Signal Pin Signal Pin Signal