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 three embedded 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 55. Processor VRM Connectors (J2A2, J2B1, J2C1): Add-in VRM Connector Pin Listing

Pin

Signal

Type*

A1

P5VIN1

POWER

A2

P5VIN2

POWER

A3

P5VIN3

POWER

A4

P12VIN1

POWER

A5

P12VIN3

POWER

A6

P1SHARE

 

A7

VID0

OUT

A8

VID2

OUT

A9

VID4

OUT

A10

VCCP1

POWER

A11

VSS1

POWER

A12

VCCP2

POWER

A13

VSS2

POWER

A14

VCCP3

POWER

A15

VSS3

POWER

A16

VCCP4

POWER

A17

VSS4

POWER

A18

VCCP5

POWER

A19

VSS5

POWER

A20

VCCP6

POWER

B1

P5VIN4

POWER

B2

P5VIN5

POWER

B3

P5VIN6

POWER

B4

P12VIN2

POWER

B5

RES

 

B6

OUTEN

OUT

B7

VID1

OUT

B8

VID3

OUT

B9

PWRGOOD

 

continued

102

SKA4 Baseboard Product Guide