Intel® 800 Series Chipset Family Platform Controller Hub (PCH), Volume 2
| ID | Date | Version | Classification |
|---|---|---|---|
| 834576 | 10/10/2024 | 001 | Public |
SW Throttle (SWTHROT) – Offset 1524
| Bit Range | Default | Access | Field Name and Description |
|---|---|---|---|
| 31:10 | 0h | RO | Reserved |
| 9:8 | 0h | RO/V | Current TState (CURRTSTATE) These bits reflect the current PCH T-state. These bits are mirrored from the PMU register. These bits also reflect the 2-bit throttle pin values that the PMC drives to other IPs 0x0 : T0 State 0x1 : T1 State 0x2 : T2 State 0x3 : T3 State |
| 7:5 | 0h | RO | Reserved |
| 4 | 0h | RW | SW Throttle Change (SWTHROT_CHANGE) SW must write this bit to 0, then 1 (edge detect) to initiate a T-state change request. The requested T-state value needs to be programmed in bits 1:0 of this register at the time of the 0->1 transition |
| 3:2 | 0h | RO | Reserved |
| 1:0 | 0h | RW | SW Throttle State (SWTHROTTSTATE) 0x0 : T0 State 0x1 : T1 State 0x2 : T2 State 0x3 : T3 State HW initiates a change to the targeted SWTHROT_TSTATE upon seeing bit 4 of this register (SWTHROT_CHANGE) change from 0 to 1. Note: Depending on other throttling modes being enabled, SW may not get its requested T-state. The deepest T-state requested by either SW, PMC or for temperature trip points being exceeded will take precedence |