Datasheet
Processor Uncore Configuration Registers
490 Datasheet, Volume 2
4.4.3.4 BIOS_MAILBOX_DATA—BIOS Mailbox Data Register
This is the Data register for the BIOS-to-PCODE mailbox. This mailbox is implemented
as a means for accessing statistics and implementing PCODE patches.
This register is used in conjunction with BIOS_MAILBOX_INTERFACE.
4.4.3.5 BIOS_MAILBOX_INTERFACE—BIOS Mailbox Interface Register
This is the Control and Status register for the BIOS-to-PCODE mailbox. This mailbox is
implemented as a means for accessing statistics and implementing PCODE patches.
This register is used in conjunction with BIOS_MAILBOX_DATA.
9:0 RW 000h
Non-Snoop Latency Value
Latency requirement for Non-Snoop requests. This value is multiplied by the
MULTIPLIER field to yield a time value, yielding an expressible range from 1ns to
34,326.183,936 ns.
Setting this field and the MULTIPLIER to all 0s indicates that the device will be
impacted by any delay and that the best possible service is requested.
PCIE_ILTR_OVRD
Bus: 1 Device: 10 Function: 1 Offset: 78h
Bit Attr
Reset
Value
Description
BIOS_MAILBOX_DATA
Bus: 1 Device: 10 Function: 1 Offset: 8Ch
Bit Attr
Reset
Value
Description
31:0 RW-V
000000
00h
Data
This field contains the data associated with specific commands.
BIOS_MAILBOX_INTERFACE
Bus: 1 Device: 10 Function: 1 Offset: 90h
Bit Attr
Reset
Value
Description
31 RW1S 0b
Run/Busy Indicator
Software may write to the two mailbox registers only when RUN_BUSY is cleared
(0b). Setting RUN_BUSY to 1b will create a Fast Path event. After setting this bit,
SW will poll this bit until it is cleared.
PCODE will clear RUN_BUSY after updating the mailbox registers with the result
and error code.
30:29 RV 0h Reserved
28:8 RW-V
000000
h
Address Range
This field contains the address associated with specific commands.
7:0 RW-V 00h
Command / Error Code
This field contains the SW request command or the PCODE response code,
depending on the setting of RUN_BUSY.
Command Encodings
01h = MAILBOX_BIOS_CMD_READ_PCS
02h = MAILBOX_BIOS_CMD_WRITE_PCS
Error Code Encodings
00h = MAILBOX_BIOS_ERROR_NONE
01h = MAILBOX_BIOS_ERROR_INVALID_COMMAND