Battery Charging Specification
`
`(Including errata and ECNs through March 15, 2012)
`Revision 1.2
`March 15, 2012
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`Copyright © 2012, USB Implementers Forum, Inc.
`All rights reserved.
`
`A LICENSE IS HEREBY GRANTED TO REPRODUCE THIS SPECIFICATION FOR
`INTERNAL USE ONLY. NO OTHER LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR
`OTHERWISE, IS GRANTED OR INTENDED HEREBY.
`
`USB-IF AND THE AUTHORS OF THIS SPECIFICATION EXPRESSLY DISCLAIM ALL
`LIABILITY FOR INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS, RELATING
`TO IMPLEMENTATION OF INFORMATION IN THIS SPECIFICATION. USB-IF AND THE
`AUTHORS OF THIS SPECIFICATION ALSO DO NOT WARRANT OR REPRESENT THAT
`SUCH IMPLEMENTATION(S) WILL NOT INFRINGE THE INTELLECTUAL PROPERTY
`RIGHTS OF OTHERS.
`
`THIS SPECIFICATION IS PROVIDED "AS IS” AND WITH NO WARRANTIES, EXPRESS OR
`IMPLIED, STATUTORY OR OTHERWISE. ALL WARRANTIES ARE EXPRESSLY
`DISCLAIMED. NO WARRANTY OF MERCHANTABILITY, NO WARRANTY OF NON-
`INFRINGEMENT, NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, AND
`NO WARRANTY ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR SAMPLE.
`
`IN NO EVENT WILL USB-IF OR USB-IF MEMBERS BE LIABLE TO ANOTHER FOR THE
`COST OF PROCURING SUBSTITUTE GOODS OR SERVICES, LOST PROFITS, LOSS OF
`USE, LOSS OF DATA OR ANY INCIDENTAL, CONSEQUENTIAL, INDIRECT, OR SPECIAL
`DAMAGES, WHETHER UNDER CONTRACT, TORT, WARRANTY, OR OTHERWISE,
`ARISING IN ANY WAY OUT OF THE USE OF THIS SPECIFICATION, WHETHER OR NOT
`SUCH PARTY HAD ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
`
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`Contributors
`Mark Lai
`Sammy Mbanta
`Abel Astley
`Kenneth Ma
`Shimon Elkayam
`Gaurav Singh
`Dan Ellis
`Graham Connolly
`Oscar Freitas
`Joel Silverman
`Pat Crowe
`Juha Heikkila
`Richard Petrie
`Sten Carlsen
`Jeroen Kleinpenning
`Terry Remple, Chair
`Dave Haglan
`Mark Bohm
`Morgan Monks
`Tim Knowlton
`Morten Christiansen
`Nicolas Florenchie
`Shaun Reemeyer
`George Paparrizos
`Adam Burns
`Wei Ming
`Jean Picard
`Ivo Huber
`Pasi Palojarvi
`Steven Tom
`Ed Beeman
`Mark Paxson
`
`Allion Test Labs
`Astec Power
`Broadcom
`Broadcom
`Broadcom
`Cypress
`DisplayLink
`Fairchild
`Fairchild
`Kawasaki
`MQP Electronics
`Nokia
`Nokia
`Nokia
`NXP Semiconductors
`Qualcomm
`SMSC
`SMSC
`SMSC
`SMSC
`ST Ericsson
`ST Ericsson
`ST Ericsson
`Summit Microelectronics
`Synopsys
`Telecommunication Metrology Center of MII
`Texas Instruments
`Texas Instruments
`Texas Instruments
`Texas Instruments
`USB-IF
`USB-IF
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`Revision History
`Revision
`Date
`BC1.0
`Mar 8, 2007
`
`Author
`Terry Remple
`
`Description
`First release
`
`BC1.1
`
`April 15, 2009 Terry Remple Major updates to all sections. Added Data Contact
`Detect protocol, and Accessory Charger Adapter.
`
`BC1.2
`
`Oct 5, 2010
`
`Terry Remple
`Adam Burns
`
`Following items indicate changes from BC1.1 to
`BC1.2. References below to Section, Figures and
`Tables refer to BC1.2, unless BC1.1 is specifically
`indicated.
`
`1. Allow DCPs to output more than 1.5A. Allows
`Portable Devices (PDs) with switch mode chargers to
`draw more power. Section 4.4.1.
`
`2. Increase minimum CDP current to 1.5A. Without
`change, PDs had to draw less than 500mA, to avoid
`CDP shutdown. Table 5-2.
`
`3. Indicate that ICDP max and IDCP max limits of 5A
`come from USB 2.0, and are safety limits. Table 5-2
`note 1.
`
`4. Allow PDs to draw up to 1.5A during HS chirp and
`traffic. Remove previous limits of 560mA and 900mA
`which was based on HS common mode ranges.
`Section 3.5.
`
`5. Require CDPs to support 1.5A during HS chirp and
`traffic. Affects CDP common mode range.
`Section 3.5.
`
`6. Reduce maximum PD current from 1.8A to 1.5A, to
`avoid shutdown when attached to CDP. Table 5-2.
`
`7. Rename Docking Station to ACA-Dock, to avoid
`confusion with other types of Docking Stations.
`
`8. Require ACA-Dock to differentiate itself from an
`ACA, by enabling VDM_SRC during no activity.
`Section 3.2.4.4.
`
`9. Allow CDP to leave VDM_SRC enabled while
`peripheral not connected. Section 3.2.4.2.
`
`10. Remove ICHG_SHTDWN. This was a recommended
`max output current for Charging Ports with VBUS
`grounded. BC1.1 Section 4.1.
`
`11. Require VDP_SRC to not pull D+ below 2.2V when
`D+ is being pulled to VDP_UP through RDP_UP.
`Require VDM_SRC to not pull D- below 2.2V when D- is
`being pulled high. Required for ACA-Dock support.
`Table 5-1 notes 1 and 2.
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`12. Make DCD current source optional for PDs.
`Section 3.2.3.
`
`13. Make DCD timeout required for PDs. Section
`3.2.3.
`
`14. Make Secondary Detection optional for PDs.
`Section 4.6.2.
`
`15. Make Good Battery Algorithm required behavior
`for PDs. Section 3.2.4.
`
`16. Remove resistive detection. BC1.1 Section 3.9.
`
`17. Change PD Required Operating Range to include
`4.5V at 500mA. Figure 4-3.
`
`18. Allow any downstream port to act as a DCP.
`Section 4.1.3.
`
`19. Require PDs to enable VDP_SRC or RDP_PU when
`charging from a DCP. Section 3.3.2.
`
`20. Allow chargers to renegotiate current with PD by
`dropping and reasserting VBUS. Section 4.1.3.
`
`21. Require PDs to discharge their own VBUS input
`after VBUS drops to support charger port
`renegotiation request. Section 4.6.3.
`
`22. Allow PDs to disconnect and repeat Charger
`Detection multiple times while attached, with specified
`timing. Section 4.6.3.
`
`23. Reduce DCP input impedance between D+, D- to
`VBUS and ground from 1MΩ to 300kΩ. Section 4.4.3.
`
`24. Require CDPs to recover after over-current
`condition. Section 4.2.2.
`
`25. Allow greater DCP undershoot for large load
`current steps, to enable low quiescent current
`chargers required by Europe. Section 4.4.2.
`
`26. Define ACAs and ACA-Docks as types of
`Charging Ports. Section 1.4.5.
`
`27. Use session valid voltage range defined in EH
`and OTG Supplement rev 2.0. Section 3.2.2.
`
`28. Only devices that can operate stand-alone from
`internal battery power are allowed to use the Dead
`Battery Provision. Section 2.2.
`
`29. Allow compound PDs to draw ISUSP plus an
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`additional ISUSP for each downstream port.
`Section 2.1.
`
`30. Remove requirement for vendors to provide
`typical and maximum connect time for products
`having a Dead or Weak Battery for compliance
`testing. Section 2.
`
`31. Remove references to no battery from Dead
`Battery Provision. Section 2.
`
`32. Require PD using Dead Battery Provision to
`enable VDP_SRC from TDBP_ATT_VDPSRC after attach to
`TDBP_VDPSRC_CON before connect. Section 2.2.
`
`33. Added DBP – Configured Clause, which allows
`PD with Dead Battery to draw ICFG_MAX for
`TDBP_FUL_FNCTN without having to pass USBCV.
`Section 2.3.
`
`34. Note constraints when trying to charge from an
`OTG A-device. Section 1.6.
`
`35. Change IDP_SINK and IDM_SINK range from
`50-150uA to 25-175uA to ease PHY design. Table 5-2
`note 1.
`
`36. Allow USB 3.0 devices to implement BC charger
`detection protocols, and to use USB 3.0 ranges for
`IUNIT and ICFG_MAX. Section 1.7.
`
`37. Rename previous ACA to Micro ACA, and define
`the Standard ACA. Section 6.
`
`38. Add caps to OTG and Accessory Ports on ACA to
`support Attach Detection Protocol (ADP). Figure 6-3.
`
`39. Change ACA ID resistance tolerances from 5% to
`1% to ease PHY design. Table 5-3.
`
`40. Remove requirements on ACA switching
`time(TACA_ID_VBUS) to ease ACA design. BC1.1
`Section 6.5.
`
`41. Add state diagram for PDs attached to ACA.
`Section 6.2.7.
`
`42. Require PDs to limit current from ACA such that
`VBUS remains above VACA_OPR. Section 6.2.2.
`
`43. Change minimum ACA operating voltage
`(VACA_OPR) from 3.0V to 4.1V. Table 5-1.
`
`44. Remove requirement that ACA VBUS resistances
`(RACA_CHG_DIS) be greater than 10k when
`VBUS_CHG is greater than 6.5V. PDs are
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`responsible for protecting themselves against higher
`voltages on VBUS. BC1.1 Section 6.7.
`
`45. Require ACAs to continue providing power to OTG
`device from Charging Port, even if ground offsets or
`USB reset cause D- to go below VDAT_REF.
`Section 6.2.6.
`
`46. Change charger shutdown recovery time
`(TSHTDWN_REC) from 2 seconds to 2 minutes. Table
`5-5.
`
`47. Indicate that ACA-Dock is required to pull D+ to
`VDP_UP with RDP_UP when VBUS is asserted.
`Section 3.2.4.4.
`
`48. Remove statements regarding devices with
`multiple receptacles. Covered in Multiple Receptacle
`white paper at http://www.usb.org/developers/docs/.
`
`49. Improve readability by adding and updating
`drawings, re-structuring sections, and clarifying text.
`
`Includes errata changes from Oct 12, 2011
`
`Includes errata changes from Mar 15, 2012:
`1. Corrections to Micro ACA specification.
`
`BC1.2
`plus errata
`BC1.2
`plus further
`errata
`
`
`
`Oct 12, 2011
`
`Pat Crowe
`
`Mar 15, 2012
`
`Pat Crowe
`
`
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`Table of Contents
`1.
`Introduction ...................................................................................................................................................... 1
`1.1 Scope ................................................................................................................................................. 1
`1.2 Background ........................................................................................................................................ 1
`1.3 Reference Documents ........................................................................................................................ 1
`1.4 Definitions of Terms ............................................................................................................................ 2
`1.4.1 Accessory Charger Adaptor .................................................................................................. 2
`1.4.2 ACA-Dock ............................................................................................................................. 2
`1.4.3 Attach versus Connect .......................................................................................................... 2
`1.4.4 Charging Downstream Port .................................................................................................. 2
`1.4.5 Charging Port ........................................................................................................................ 2
`1.4.6 Dead Battery Threshold ........................................................................................................ 2
`1.4.7 Dedicated Charging Port ...................................................................................................... 3
`1.4.8 Downstream Port .................................................................................................................. 3
`1.4.9 Micro ACA ............................................................................................................................. 3
`1.4.10 Portable Device..................................................................................................................... 3
`1.4.11 Rated Current ....................................................................................................................... 3
`1.4.12 Standard ACA ....................................................................................................................... 3
`1.4.13 Standard Downstream Port .................................................................................................. 3
`1.4.14 USB Charger ......................................................................................................................... 3
`1.4.15 Weak Battery Threshold ....................................................................................................... 3
`1.5 Parameter Values ............................................................................................................................... 4
`1.6 OTG Considerations ........................................................................................................................... 4
`1.7 Super Speed Considerations ............................................................................................................. 4
`2. Dead Battery Provision .................................................................................................................................... 4
`2.1 Background ........................................................................................................................................ 4
`2.2 DBP – Unconfigured Clause .............................................................................................................. 4
`2.3 DBP – Configured Clause .................................................................................................................. 5
`3. Charging Port Detection .................................................................................................................................. 6
`3.1 Overview ............................................................................................................................................. 6
`3.2 Charger Detection Hardware .............................................................................................................. 7
`3.2.1 Overview ............................................................................................................................... 8
`3.2.2 VBUS Detect ......................................................................................................................... 8
`3.2.3 Data Contact Detect ............................................................................................................. 9
`3.2.4 Primary Detection ............................................................................................................... 14
`3.2.5 Secondary Detection .......................................................................................................... 22
`3.2.6 ACA Detection .................................................................................................................... 25
`3.3 Charger Detection Algorithms .......................................................................................................... 28
`3.3.1 Weak Battery Algorithm ...................................................................................................... 28
`3.3.2 Good Battery Algorithm ...................................................................................................... 30
`3.4 Charger Detection Timing................................................................................................................. 32
`3.4.1 Data Contact Detect Timing ................................................................................................ 32
`3.4.2 Detection Timing, CDP ....................................................................................................... 35
`3.5 Ground Current and Noise Margins ................................................................................................. 36
`4. Charging Port and Portable Device Requirements .................................................................................... 37
`4.1 Charging Port Requirements ............................................................................................................ 37
`4.1.1 Overshoot ........................................................................................................................... 37
`4.1.2 Maximum Current ............................................................................................................... 37
`4.1.3 Detection Renegotiation ..................................................................................................... 37
`4.1.4 Shutdown Operation ........................................................................................................... 37
`4.1.5 Failure Voltage .................................................................................................................... 37
`4.1.6 Multiple Ports ...................................................................................................................... 37
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`4.2 Charging Downstream Port .............................................................................................................. 38
`4.2.1 Required Operating Range ................................................................................................. 38
`4.2.2 Shutdown Operation ........................................................................................................... 38
`4.2.3 Undershoot ......................................................................................................................... 39
`4.2.4 Detection Signaling ............................................................................................................. 39
`4.2.5 Connector ........................................................................................................................... 39
`4.3 ACA-Dock ......................................................................................................................................... 39
`4.3.1 Required Operating Range ................................................................................................. 39
`4.3.2 Undershoot ......................................................................................................................... 39
`4.3.3 Detection Signaling ............................................................................................................. 39
`4.3.4 Connector ........................................................................................................................... 39
`4.4 Dedicated Charging Port .................................................................................................................. 40
`4.4.1 Required Operating Range ................................................................................................. 40
`4.4.2 Undershoot ......................................................................................................................... 41
`4.4.3 Detection Signaling ............................................................................................................. 41
`4.4.4 Connector ........................................................................................................................... 41
`4.5 Accessory Charger Adapter ............................................................................................................. 41
`4.5.1 Required Operating Range ................................................................................................. 41
`4.5.2 Undershoot ......................................................................................................................... 41
`4.5.3 Detection Signaling ............................................................................................................. 41
`4.5.4 Connector ........................................................................................................................... 42
`4.6 Portable Device ................................................................................................................................ 42
`4.6.1 Allowed Operating Range ................................................................................................... 42
`4.6.2 Detection Signaling ............................................................................................................. 42
`4.6.3 Detection Renegotiation ..................................................................................................... 43
`4.6.4 Connector ........................................................................................................................... 43
`5. Parameter Values ........................................................................................................................................... 44
`6. Accessory Charger Adapter ......................................................................................................................... 49
`6.1
`Introduction ....................................................................................................................................... 49
`6.2 Micro ACA ........................................................................................................................................ 50
`6.2.1 Micro ACA Ports ................................................................................................................. 50
`6.2.2 Micro ACA Connectivity Options ......................................................................................... 51
`6.2.3 Micro ACA Architecture ...................................................................................................... 52
`6.2.4 Micro ACA Modes of Operation .......................................................................................... 53
`6.2.5
`Implications of not Supporting Micro ACA Detection .......................................................... 54
`6.2.6 Micro ACA Requirements ................................................................................................... 54
`6.2.7 Portable Device State Diagram .......................................................................................... 56
`6.3 Standard ACA ................................................................................................................................... 58
`6.3.1 Standard ACA Ports ........................................................................................................... 58
`6.3.2 Standard ACA Architecture ................................................................................................. 59
`6.3.3 Standard ACA Modes of Operation .................................................................................... 60
`6.3.4
`Implications of not Supporting Standard ACA Detection .................................................... 61
`6.3.5 Standard ACA Requirements ............................................................................................. 61
`
`
`
`
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`Figures
`Figure 3-1 System Overview ............................................................................................................................. 6
`Figure 3-2 Charger Detection Hardware ........................................................................................................... 8
`Figure 3-3 Data Pin Offset .............................................................................................................................. 10
`Figure 3-4 Data Contact Detect, Not Attached ............................................................................................... 11
`Figure 3-5 Data Contact Detect, Standard Downstream Port ......................................................................... 13
`Figure 3-6 Primary Detection, DCP ................................................................................................................ 14
`Figure 3-7 Primary Detection, CDP ................................................................................................................ 16
`Figure 3-8 Primary Detection, SDP ................................................................................................................. 18
`Figure 3-9 Primary Detection, ACA-Dock ....................................................................................................... 19
`Figure 3-10 Primary Detection, ACA ............................................................................................................... 21
`Figure 3-11 Secondary Detection, DCP .......................................................................................................... 23
`Figure 3-12 Secondary Detection, CDP .......................................................................................................... 24
`Figure 3-13 ACA Detection ............................................................................................................................. 26
`Figure 3-14 Weak Battery Algorithm ............................................................................................................... 28
`Figure 3-15 Good Battery Algorithm ............................................................................................................... 30
`Figure 3-16 DCD Timing, Contact After Start ................................................................................................. 32
`Figure 3-17 DCD Timing, Contact Before Start .............................................................................................. 33
`Figure 3-18 DCD Timing, No Contact ............................................................................................................. 34
`Figure 3-19 Detection Timing, CDP ................................................................................................................ 35
`Figure 4-1 CDP Required Operating Range ................................................................................................... 38
`Figure 4-2 DCP Required Operating Range ................................................................................................... 40
`Figure 4-3 Portable Device Allowed Operating Range ................................................................................... 42
`Figure 6-1 Accessory Charger Adapter .......................................................................................................... 49
`Figure 6-2 Micro ACA Ports ............................................................................................................................ 50
`Figure 6-3 Micro ACA Architecture ................................................................................................................. 52
`Figure 6-4 Portable Device State Diagram ..................................................................................................... 56
`Figure 6-5 Standard ACA Ports ...................................................................................................................... 58
`Figure 6-6 Standard ACA Architecture ........................................................................................................... 59
`
`
`Tables
`Table 5-1 Voltages .......................................................................................................................................... 44
`Table 5-2 Currents .......................................................................................................................................... 45
`Table 5-3 Resistances .................................................................................................................................... 46
`Table 5-4 Capacitances .................................................................................................................................. 47
`Table 5-5 Times .............................................................................................................................................. 48
`Table 6-1 Micro ACA Connectivity Options ..................................................................................................... 51
`Table 6-2 Micro ACA Modes of Operation ...................................................................................................... 53
`Table 6-3 Standard ACA Connectivity Options ............................................................................................... 59
`Table 6-4 Standard ACA Modes of Operation ................................................................................................ 60
`
`
`
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`
`
`ACA
`CDP
`DBP
`DCD
`DCP
`FS
`HS
`LS
`OTG
`PC
`PD
`PHY
`PS2
`SDP
`SRP
`TPL
`USB
`USBCV
`USB-IF
`VBUS
`
`
`Acronyms
`
`Accessory Charger Adapter
`Charging Downstream Port
`Dead Battery Provision
`Data Contact Detect
`Dedicated Charging Port
`Full Speed
`High-Speed
`Low-Speed
`On-The-Go
`Personal Computer
`Portable Device
`Physical Layer Interface for High-Speed USB
`Personal System 2
`Standard Downstream Port
`Session Request Protocol
`Targeted Peripheral List
`Universal Serial Bus
`USB Command Verifier
`USB Implementers Forum
`Voltage line of the USB interface
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`1. Introduction
`
`1.1 Scope
`The Battery Charging Working Group is chartered with creating specifications that define limits as well as
`detection, control and reporting mechanisms to permit devices to draw current in excess of the USB 2.0
`specification for charging and/or powering up from dedicated chargers, hosts, hubs and charging
`downstream ports. These mechanisms are backward compatible with USB 2.0 compliant hosts and
`peripherals.
`
`
`1.2 Background
`The USB ports on personal computers are convenient places for Portable Devices (PDs) to draw current for
`charging their batteries. This convenience has led to the creation of USB Chargers that simply expose a
`USB standard-A receptacle. This allows PDs to use the same USB cable to charge from either a PC or from
`a USB Charger.
`
`If a PD is attached to a USB host or hub, then the USB 2.0 specification requires that after connecting, a PD
`must draw less than:
`• 2.5 mA average if the bus is suspended
`• 100 mA if bus is not suspended and not configured
`• 500 mA if bus is not suspended and configured for 500 mA
`
`
`If a PD is attached to a Charging Port, (i.e. CDP, DCP, ACA-Dock or ACA), then it is allowed to draw
`IDEV_CHG without having to be configured or follow the rules of suspend.
`
`In order for a PD to determine how much current it is allowed to draw from an upstream USB port, there
`need to be mechanisms that allow the PD to distinguish between a Standard Downstream Port and a
`Charging Port. This specification defines just such mechanisms.
`
`Since PDs can be attached to USB chargers from various manufacturers, it is important that all provide an
`acceptable user experience. This specification defines the requirements for a compliant USB charger, which
`is referred to in this spec as a USB Charger.
`
`If a PD has a Dead or Weak Battery, then the Connect Timing Engineering Change Notice (ECN) issued by
`the USB-IF on the USB 2.0 spec allows that device to draw up to IUNIT while attached but not connected.
`The conditions associated with this ECN are contained in Section 2 of this specification, and are referred to
`as the Dead Battery Provision (DBP).
`
`1.3 Reference Documents
`The following specifications contain information relevant to the Battery Charging Specification.
`
`
`• OTG and Embedded Host Supplement, Revision 2.0
`• USB 2.0 Specification
`• USB 3.0 Specification
`
`
`
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`1.4 Definitions of Terms
`This section contains definitions for some of the terms used in this specification.
`
`1.4.1 Accessory Charger Adaptor
`An Accessory Charger Adaptor (ACA) is an adaptor which allows a single USB port to be attached to both a
`charger and another device at the same time.
`
`The following terminology is used when referring to an ACA:
`
`
`An ACA with ID resistance of RID_A
`An ACA with ID resistance of RID_B
`An ACA with ID resistance of RID_C
`
`• ACA-A
`• ACA-B
`• ACA-C
`
`See Section 6 for details on an ACA.
`
`1.4.2 ACA-Dock
`An ACA-Dock is a docking station that has one upstream port, and zero or more downstream ports. The
`upstream port can be attached to a PD, and is capable of sourcing ICDP to the PD. An ACA-Dock signals it
`is an ACA-Dock to the PD by enabling VDM_SRC during USB idle, and by pulling ID to ground through a
`resistance of RID_A. See Section 3.2.4.4 for more details.
`
`1.4.3 Attach versus Connect
`This specification makes a distinction between the words “attach” and “connect”. A downstream device is
`considered to be attached to an upstream port when there is a physical cable between the two.
`
` A
`
` downstream device is considered to be connected to an upstream port when it is attached to the upstream
`port, and when the downstream device has pulled either the D+ or D- data line high through a 1.5 kΩ
`resistor, in order t