Intel® 400 Series Chipset On-Package Platform Controller Hub
Online Register Database
Host Control 2 (hostcontrol2) – Offset 3e
Bit Range | Default | Access | Field Name and Description |
---|---|---|---|
15 | 0h | RW | Preset Value Enable (hostctrl2_presetvalueenable) Host Controller Version 3.00 supports this bit. As theoperating SDCLK frequency and I/O driver strengthdepend on the Host System implementation, it isdifficult to determine these parameters in the StandardHost Driver.When Preset Value Enable is set to automatic. This bitenables the functions defined in the Preset Valueregisters.1 Automatic Selection by Preset Value are Enabled0 SDCLK and Driver Strength are controlled by HostDriver. |
14 | 0h | RW | Asynchronous Interrupt Enable (hostctrl2_asynchintrenable) This bit can be set to 1 if a card support asynchronousinterrupt and Asynchronous Interrupt Support is set to 1in the Capabilities register. |
13:10 | - | - | Reserved
|
9 | 0h | RW | Driver Strength Select (hostctrl2_driverstrength) Host Controller output driver in 1.8V signaling isselected by this bit. In 3.3V signaling, this field is noteffective. |
8 | - | - | Reserved
|
7 | 0h | RW | Sampling Clock Select (hostctrl2_samplingclkselect) This bit is set by tuning procedure when Execute Tuningis cleared. Writing 1 to this bit is meaningless andignored. Setting 1 means that tuning is completedsuccessfully and setting 0 means that tuning is failed. Controller is receiving response or a read data block. |
6 | 0h | RW | Execute Tuning (hostctrl2_executetuning) This bit is set to 1 to start tuning procedure andautomatically cleared when tuning procedure iscompleted. The result of tuning is indicated to SamplingClock Select. Tuning procedure is aborted by writing 0for more detail about tuning procedure. |
5:4 | - | - | Reserved
|
3 | 0h | RW | 1.8V Signaling Enable (hostctrl2_1p8vsignallingena) This bit controls voltage regulator for I/O cell. 3.3V issupplied to the card regardless of signaling voltage.Setting this bit from 0 to 1 starts changing signal voltagefrom 3.3V to 1.8V. |
2:0 | 0h | RW | UHS Mode Select (hostctrl2_uhsmodeselect) This field is used to select one of UHS-I modes andeffective when 1.8V Signaling Enable is set to 1. |