Intel E7-2803 AT80615006438AB User Manual
Product codes
AT80615006438AB
Datasheet Volume 2 of 2
49
Power Management Architecture (Wbox)
Intel Xeon Processor E7-8800/4800/2800 Product Families expects mailbox sideband
limit request as core clock multiplier ratio corresponding to a valid P-state defined in
ACPI table (ACPI table is visible to PECI Host Controller). The pcode support for
mailbox interface will be designed to accept all possible P-states (clock ratios) limit
requests, it will allow design flexibility to add any new p-state between P1 and Pn. it
expects from PECI host to request only valid P-state same as defined in ACPI table.
limit request as core clock multiplier ratio corresponding to a valid P-state defined in
ACPI table (ACPI table is visible to PECI Host Controller). The pcode support for
mailbox interface will be designed to accept all possible P-states (clock ratios) limit
requests, it will allow design flexibility to add any new p-state between P1 and Pn. it
expects from PECI host to request only valid P-state same as defined in ACPI table.
9.8.3
MAILBOX_READ_P_STATE_LIMIT (request type = 0x24)
This mailbox command is used by PECI host to readout socket's current sideband P-
state limit. The response data will reflect any clipping applied on this limit internally by
sockets.
state limit. The response data will reflect any clipping applied on this limit internally by
sockets.
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