RELEASE NOTES
=============
Silicon Labs Virtual COM Port (VCP) driver for Windows

Package version: 6.7.6
Release date:    2018-06-05

This package contains a Virtual COM Port driver for Microsoft Windows
for use with Silicon Labs VCP USB Serial Bridges.  These devices include
the CP2102N, CP2102, CP2103, CP2104, CP2105, CP2108, CP2109.

OS VERSIONS
-----------
This package provides the CP210x VCP driver for the following versions
of Windows:

- Windows 8.1   (x86 32/64 bit)
- Windows 8     (x86 32/64 bit)
- Windows 7     (x86 32/64 bit)

CONTENTS
--------
The VCP driver package contains the following files and directories:
- slabvcp.inf -- Driver information file
- CP210xVCPInstaller_x64.exe -- 64-bit installer
- CP210xVCPInstaller_x86.exe -- 32-bit installer
- SLAB_License_Agreement_VCP_Windows.txt -- Software License
- v6-7-6-driver-release-notes.txt -- this file

Additional files needed by installer
- dpinst.xml
- slabvcp.cat
- x64/
- x86/

INSTALLING
----------
The VCP driver is automatically installed by Windows Update for CP210x with
alternate PID values of 0xEA63, 0xEA7A, and 0xEA7B.  These are not default
values.

Otherwise, unzip the .zip file and you will have a directory containing the
driver installer files.

### Prompted install ###

If Windows prompts you to install a driver for a CP210x device
(for example, if you plug a CP210x into your computer):

1. Use the dialog to browse for the driver location
2. Locate the driver folder (that you previously unzipped)
3. Follow the instructions

### Manual install ###

1. Using Windows File Explorer, locate the driver folder
   (that you previously unzipped)
2. Determine if you have 32-bit or 64-bit Windows
3. Double click to run the .exe file named CP210xVCPInstaller_xnn.exe
   (where xnn is x64 for 64-bit and x86 is for 32-bit)
4. Follow the instructions

UNINSTALLING
------------
1. The device must be plugged in
2. Run Device Manager
3. Locate the device you want to uninstall
4. Right click on the device and choose "uninstall"
5. Follow the instructions

SUPPORT
-------
For technical support please visit the Silicon Labs support site:

https://www.silabs.com/support

******************************************************************************
    RELEASE NOTES FOR 6.7.6 (2018-06-05)

Changes for VCP Driver
==============================================================================
MCUSW-326    | Clear DTR on CloseHandle().                                     



MCUSW-134    | Fixed an issue with handling of IOCTL_SERIAL_SET_WAIT_MASK,
             | IOCTL_SERIAL_WAIT_ON_MASK, with the SERIAL_EV_RXCHAR event
             | and data arriving from the device into the driver. Previously,
             | an indication of arriving data was made before making the data
             | available, causing, in some conditions, subsequent requests
             | for data after notification of data available to not deliver
             | any data. 
MCUSW-288    | Fix IOCTL_SERIAL_GET_PROPERTIES.                                
MCUSW-291    | Fix IOCTL_SERIAL_GET_PROPERTIES/SERIAL_COMMPROP for CP210x-like 
             | "Voice MB v2.0" device.                                         

			 
******************************************************************************
    RELEASE NOTES FOR 6.7.5 (2017-10-13)

Changes for VCP Driver
==============================================================================
MCUSW-17     | IOCTL_SERIAL_GET_STATUS TransmittedCount fixed.                 
MCUSW-19     | CP210x_GET_CONFIG_DESCRIPTOR_IOCTL returned byte count fixed.   
MCUSW-21     | Revert IOCTL_SERIAL_GET_COMMSTATUS behaviour to return cached   
             | information (reverse slowdown reported with v6.7.4 in some      
             | applications)                                                   
             |                                                                 
             | Improve windbg logging, w.r.t. doing less when logging is not   
             | enabled (say, Release builds), or when particular subsystem is  
             | not enabled for logging.                                        
             |                                                                 
MCUSW-110    | Windows 10 certified against RS2 (Creators Update).             
MCUSW-207    | In a failed initialization, discard a reference to dynamically  
             | allocated memory once memory has been freed.                    
MCUSW-234    | timestamp SHA2 Signatures with SHA2 timestamps                  



******************************************************************************
    RELEASE NOTES FOR 6.7.4.261 (2017/01/30)

- Device Guard compliant
- CP210XFW-747: Add 3 new parallel PIDs one each for the single-, dual- &
  quad-port CP210x devices (to be distributed via Windows Update)
- CP210XFW-741: Fix driver to use correct interface string index for the
  multi-interface CP210x devices (CP2105 & CP2108). Return iProduct string
  for other CP210x devices.
- CP210XFW-713: Add protection against IRP_MJ_CLOSE coming before
  IRP_MJ_CLEANUP. In such case EvtFileCleanup callback was called with 0
  FileObject, causeing a crash. Serenum is suspected of causing this, even
  though there is no proof except that it's present, was introduced recently
  and this crash was never registered before.
- CP210XFW-691: Fixed race between timer activation and request cancelation
  during processing of read rwquests.
- Changed raw WDF read request timer to our wrapper.
- CP210XFW-693: bugfix: WMI command "wmic path Win32_SerialPort get
  Availability^, DeviceID^, Name" is unable to enumerate the port.
- CP210XFW-686: EvtRequestCancel for wait mask IRP crashed because the
  request was already completed. It didn't serialize well with other places
  that can complete it. It looked like XOff IRP may have the same proble. This
  patch is adding an extra check into *all* other EvtRequestCancel functions
  to make sure this doesn't happen again.
- Changed IOCTLs returning polled-cached MDMSTS to explicitly read the
  status. Use reg value DisableHwAccessInModemStatusIoctls to revert this
  new functionality to old behavior.
- Improved debug prints.
- SerialDbgPrintEx used 1K of stack for the string, reduced to 256.
- Resolved many static Code Analysis warnings
- Added accounting for data in chip's TX queue. Added translation of
  COMM_STATUS::ulErrors into SERIAL_EV_BREAK and SERIAL_EV_ERR.
- CP210XFW-549, CP210XFW-536, CP210XFW-546: Generate events for
  IOCTL_SERIAL_SET_WAIT_MASK from COMM_STATUS::ulErrors. Can be disabled by
  DisableCommStatusPolling reg value.
- Added spinlock around ModemStatus change detection. Refactored modem
  status event signalling to use common function.
- Move passive level functions into the paged section.
- MCUFW-740: Made device close operation wait for chip's Tx queue to empty.
  Added registry settings DisableTxEmptyCheckInClose and
  TxEmptyTimeoutOnCloseInMs.
- Improve control transfer debug prints and clean up code, otherwise no
  functional changes.
- MCUFW-740: Fixed EV_TXEMPTY to account for bytes in chip's Tx queue.
- MCUFW-740: New functions to sync access to comm error storage from
  multiple threads.
- Added DisableTxEmptyCheckInGetCommStatusIoctl reg value.
- Refactor control request I/O. MCUFW-740: Fixed
  IOCTL_SERIAL_GET_COMMSTATUS.
- MCUFW-740: Made device close operation wait for chip's Tx queue to empty.
  Added registry settings DisableTxEmptyCheckInClose and
  TxEmptyTimeoutOnCloseInMs.
- CP210XFW-648: Set a three second timeout on
  WdfUsbTargetDeviceSendControlTransferSynchronously().

******************************************************************************
    RELEASE NOTES FOR 6.7.3 (2016/03/03)

- Down-rev the verison of KMDF the driver uses (CP210XFW-591. Use version of
  KMDF natively included on Windows release)
- Bug fix of blue-screen system crash (CP210XFW-575. driver tries to clear a
  Cancel Routine in a Request that doesn't have it.)

******************************************************************************
    RELEASE NOTES FOR 6.7.2 (2015/11/23)

- Unified Windows 7, 8, 8.1 & 10 support (XP, Vista and Server 2003
  available in version 6.7).
- ARM support added for Windows 10 and Windows 10 IoT Core.
- Silicon Labs-specific Serial Enumeration driver silabenm removed in favor
  of the Windows "in-box" serenm.
- UpperFilter Serial Enumeration driver not enabled by default
- Updated to latest Microsoft build tools
- Resolved /W4 compilation warnings
- Resolved code analysis warnings
- Added a registry value ControlHandShakeForcedSetBits that can force
  certain bits in the ControlHandShake variable to always be set.
- Add SAL-annotations to API header files.
- Bugfix an invalid memory access on device stop.
- Standardize branding Properties resources across all deliverables.
- Digitally sign all signable deliverables.
- Rewrote driver synchronization for data transmission paths.
- Resolve bugs arising from extended stress test.
- Added diagnostic variables to device extension.
- Bugfix a Write IRP stuck forever cauding bugcheck 9f-4 if call to USB
  returns with error.
- Bugfix "packetized write" timeout may fail to act. And improved debug
  prints.
- New reg value DisableS0Idle (default: 0) to replace EnablePowerManagewment
  (default: 0 which actually ment "enable"). Also, DisableS0Idle=1 now
  forces AllowIdleWhileOpen to 0.
- Driver ignores BreakOnEntry, DebugLevel and DebugFlag in registry.
- New CP2108 bug workarounds - GET_LINE_CTL byte swap and tx_empty().
- Fixed crash in read path.
- Simplified, commented and synchronized with NEWSTUFF EvtIoStop and
  EvtIoResume.
- Fixed memory leak on device removal when multiple devices are present.
- Bugfix Read IRP may never complete if other read IRPs are already waiting
  when it arrives.
- Add CP2102N part numbers. Hnadle new part numbers in
  WriteLatch()/ReadLatch().
- Resolve HCK INF warnings that became errors on HLK.
- Bugfix: Potential invalid memory access on device stop.
- Fixed possible memory overrun when writing CP2108 latch.
- Cumulative collection of improvements (due to code analysis, application
  of latest toolset, etc.) and bug fixes.

******************************************************************************
    RELEASE NOTES FOR 6.7.1 (2015/06/29)

- Added certification for Windows 10 Preview (Note: Windows 10 only;
  use v6.7 for Windows prior to Windows 10)

******************************************************************************
    RELEASE NOTES FOR 6.7 (2014/04/11)

- Added vendor-specific commands to the driver that do not affect normal
  operation with standard CP210x devices.
- Modified write behavior to packetize data as a work around for a rare
  USB 2.0 hub behavior seen only in Windows XP (x86).

******************************************************************************
    RELEASE NOTES FOR 6.6.1 (2013/10/24)

- Added certification for Windows 8.1
- Added support for CP2108 devices
- Corrected bug where OS would hang on repetition of many rapid open/closes on
  certain systems.

******************************************************************************
    RELEASE NOTES FOR 6.6

- Moving installer format to DPInst
- Supported under Windows 8
- Corrected bug in total write timeout calculation
- Corrected bug where EV_BREAK event could be misreported based on incoming
  data
- Corrected another BSOD corner case regarding write cancellation

******************************************************************************
    RELEASE NOTES FOR 6.5.3

- Corrected BSOD corner case for a write cancellation
- Corrected memory leak that occurs when a device is plugged/unplugged
  rapidly enough to allow driver startup function to fail

******************************************************************************
    RELEASE NOTES FOR 6.5

- Corrected BSOD corner case issue for handling control requests
- Corrected issue where USB 3.0 hubs would deliver data to the driver out
  of order

******************************************************************************
    RELEASE NOTES FOR 6.4

- Corrected multiple BSOD issues by updating request handling for control
  requests to the USB device, and the write completion method
- Corrected device removal routine to also undo the COM port naming in the
  registry at removal time instead of when the device is closed after the
  removal.

******************************************************************************
    RELEASE NOTES FOR 6.3a

- Updated to 3.2 DriverInstaller to correct a bug seen when updating from an
  old driver installer version	

******************************************************************************
    RELEASE NOTES FOR 6.3

- Corrected a bug introduced in 6.2 which caused BSOD during surprise removal.
- Corrected a bug found in I/O cancellation corner case

******************************************************************************
    RELEASE NOTES FOR 6.2

- Corrected return value for DeviceIoControl() and other COM API functions
  once the device is removed to properly show ERROR_ACCESS_DENIED (0x05)
  instead of ERROR_BAD_COMMAND in GetLastError()
- Corrected bug in DTR/RTS reporting latency seen if you set DTR/RTS and ask
  for it before the device has reported it to the host - now when it is
  written it reads back immediately
- Corrected several USB requests that were improperly defined as device
  requests when they are actually interface requests - this doesn't exhibit
  and bugs in current single interface devices but was changed to be complete
  and correct
- Added support for CP2104 and CP2105 devices	

******************************************************************************
    RELEASE NOTES FOR 6.1

- Corrected a memory leak which could bog the system down after extended use
  of a contiuously opened COM port, and conditionally yield bluescreens on
  certain systems
- Corrected a problem where an IO reqest would sometimes return a busy
  status to user mode, instead the queue is restarted if necessary before
  adding an IO request to the queue
- Corrected a condition which would blue screen on cancelling write request
  that hasn't been fully sent out USB
- Corrected the Capabilites return value, which incorrectly reported that
  timeouts are not supported
- Corrected several Queue size return values, which affected behavior in the
  MSCOMM control
- Corrected DTR/RTS value on device insertion, visible when Serial
  Enumeration is disabled
- Corrected the ability to override Baud Rate and Line Control from the INF
  file

******************************************************************************
    RELEASE NOTES FOR 6.0

- Corrected multiple blue screens and driver hangs related to race
  conditions in the driver
- Corrected problem where driver hangs when 4 or more devices are connected
  to a single transaction translator hub
- Corrected bugs that prohibited serial enumeration
- Corrected problem where IO requests were not completed/cancelled on a
  close
- Corrected problem with dialing out or PPP connections
- Created IO queueing mechanism so that multiple reads, writes, etc. can be
  queued and waited on

