Intel® Core™ Ultra Processors for H-series and U-series Platforms CFG and MEM Registers
| ID | Date | Version | Classification |
|---|---|---|---|
| 795258 | 07/29/2024 | Public |
MemSS PMA BIOS request register (MEMSS_PMA_CR_BIOS_REQ) – Offset 13d08
This register is used as interface between MRC and MemSS PMA during memory initialization and training to communicate Qclk target ratio. Register must be locked after MRC_DONE.
| Bit Range | Default | Access | Field Name and Description |
|---|---|---|---|
| 31 | 0h | RW/V | Run Busy bit (RUN_BUSY) Run busy bit set by MRC to inform MemSS PMA of new Qclk point request. |
| 30:29 | 0h | RW | QCLK WP Index (QCLK_WP_IDX) QClk WP index to be passed on to DDR PHY PMA |
| 28:9 | 0h | RW | Max Bandwidth MBps (MAX_BW_MBPS) Maximum theoritical bandwidth supported at the request Qclk frequency in MB/s in the current memory configuration. Bandwidth is calculated as: "BW (MB/s) = Data Rate (MT/s) * Number of populated channels * Channel width (B)". Maximum number of populated channels are 8 for LP4/5 and 4 for DDR5. Channel width is 2 bytes for LP4/5 and 4 bytes for DDR5. |
| 8 | 0h | RW | Gear Type (GEAR_TYPE) Gear Type associated with requested Qclk ratio. |
| 7:0 | 0h | RW | Qclk ratio (QCLK_RATIO) Qclk ratio with reference of 33.33MHz. |