Intel® 800 Series Chipset Family Platform Controller Hub (PCH), Volume 2
ID | Date | Version | Classification |
---|---|---|---|
834576 | 10/10/2024 | 001 | Public |
Inbound DoorbellHOST To ISH (HOST2ISH_DOORBELL_HOST) – Offset 48
Inbound doorbell register, from HOST core to interrupt ISH. Data 30:0 is 31bits message payload used for backward compatibility. Software can use either this 31bit message payload or 256bit payload registers. When software writes the message in to respective message register, it should set bit 31(BUSY Bit) of doorbell register to indicate that new data is written. The ISH will assert a level sensitive interrupt to the IOAPIC as long as the BUSY bit is set. When the ISH reads the message code from this register it should write back to this register and clear the BUSY bit.
Bit Range | Default | Access | Field Name and Description |
---|---|---|---|
31 | 0h | RW | HOST2ISH Doorbell Busy Bit (BUSY) When this bit is cleared, the ISH CPU is Ready to accept a new message. |
30:0 | 0h | RW | HOST2ish Doorbell Payload (PAYLOAD_31BIT) 31bits message payload for backward compatibility. |