Zynq UltraScale+ Devices Register Reference > Module Summary > USB3_XHCI Module > PORTPMSC_20 (USB3_XHCI) Register

PORTPMSC_20 (USB3_XHCI) Register

PORTPMSC_20 (USB3_XHCI) Register Description

Register NamePORTPMSC_20
Relative Address0x0000000424
Absolute Address 0x00FE200424 (USB3_0_XHCI)
0x00FE300424 (USB3_1_XHCI)
Width32
TypemixedMixed types. See bit-field details.
Reset Value0x00000000
DescriptionUSB3 Port Power Management Status and Control Register Bit Definitions
This register is in the Aux Power well. It is only reset by platform hardware during a cold reset or in response to a Host Controller Reset (HCRST).
Programming this field with random data will cause side effect i.e. Register Access will fail (Timeout) if the pipe clock is not running or reset is asserted. Bit Bash register testing is not recommended.

PORTPMSC_20 (USB3_XHCI) Register Bit-Field Summary

Field NameBitsTypeReset ValueDescription
PRTTSTCTRL31:28rwNormal read/write0Port Test Control
For a description of this standard USB register field, see the eXtensible Host Controller Interface for Universal Serial Bus (USB) Specification 3.0.
Reserved27:17roRead-only0x0Reserved
HLE16rwNormal read/write0Port Test Control
For a description of this standard USB register field, see the eXtensible Host Controller Interface for Universal Serial Bus (USB) Specification 3.0.
L1DSLOT15:8rwNormal read/write0L1DSLOT
For a description of this standard USB register field, see the eXtensible Host Controller Interface for Universal Serial Bus (USB) Specification 3.0.
HIRD 7:4rwNormal read/write0Host Initiated Resume Duration (HIRD) - RW.
Default = 0. System software sets this field to indicate to the recipient device how long the xHC will drive resume if it (the xHC) initiates an exit from L1.
The HIRD value is encoded as follows: Value Description 0h 50us. (default) 1h 125us. 2h 200us.
Fh 1.175 ms. The value of 0000b is interpreted as 50us. Each incrementing value up adds 75us. to the previous value.
For example, 0001b is 125us, 0010b is 200us and so on. Based on this rule, the maximum value resume drive time is at encoding value 1111b which represents 1.2ms.
Note that the HIRD field is used by both software and hardware controlled LPM.
Refer to section 4.23.5.1.1 for more information on HIRD use. Refer to Section 4.1 of the USB2 LPM spec for more information on the use of the HIRD field.
RWE 3rwNormal read/write0Port Test Control
For a description of this standard USB register field, see the eXtensible Host Controller Interface for Universal Serial Bus (USB) Specification 3.0.
L1S 2:0roRead-only0L1 Status (L1S) - RO. Default = 0.
This field is used by software to determine whether an L1-based suspend request (LMP transaction) was successful, specifically:
Value Meaning 0 Invalid - This field is ignored by software.
- 1 Success - Port successfully transitioned to L1 (ACK)
- 2 Not Yet - Device is unable to enter L1 at this time (NYET)
- 3 Not Supported -Device does not support L1 transitions (STALL)
- 4 Timeout/Error -Device failed to respond to the LPM Transaction or an error occurred
- 5-7 Reserved The value of this field is only valid when the port resides in the L0 or L1 state (PLS = 0 or 2).
Refer to section 4.23.5.1.1 for more information.