XR17V354

High Performance Quad PCI Express UART
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Overview

Information High Performance Quad PCI Express UART
Data Bus Interface PCIe 2.0 (2.5Gbps)
# of Channels 4
Max Data Rate (Mbps) 31.25
Tx/Rx FIFO (Bytes) 256/256
FIFO Level Counters
Program. Trigger Levels
Auto Flow Control
Auto RS-485 Half-Duplex Control
Multidrop (9-bit) Mode
Fractional Baud Rate Generator
Power Down Mode
5V Tolerant Inputs
IrDA Sup
Supply Voltage Range VCC (V) 3 to 3.6
No. of GPIOs 16
Max UART/GPIO Input Voltage (V) VCC
Max UART/GPIO Output Voltage (V) VCC
Temperature Range (°C) -40 to 85
Package FPBGA-176
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The XR17V354¹ ((V354) is a single chip 4-channel PCI Express (PCIe) UART (Universal Asynchronous Receiver and Transmitter), optimized for higher performance and lower power. The V354 serves as a single lane PCIe bridge to 4 independent enhanced 16550 compatible UARTs. The V354 is compliant to PCIe 2.0 Gen 1 (2.5GT/s).

In addition to the UART channels, the V354 has 16 multi-purpose I/Os (MPIOs), a 16-bit general purpose counter/timer and a global interrupt status register to optimize interrupt servicing.

Each UART of the V354 has many enhanced features such as the 256-bytes TX and RX FIFOs, programmable Fractional Baud Rate Generator, Automatic Hardware or Software Flow Control, Auto RS-485 Half-Duplex Direction Control, programmable TX and RX FIFO Trigger Levels, TX and RX FIFO Level Counters, infrared mode, and data rates up to 31.25Mbps. The V354 is available in a 176-pin fpBGA package (13 x 13 mm).

NOTE¹: Covered by U.S. Patents #5,649,122, #6,754,839, #6,865,626 and #6,947,999


  • Single 3.3V power supply
  • Internal buck regulator for 1.2V core
  • PCIe 2.0 Gen 1 compliant
  • x1 Link, dual simplex, 25Gbps in each direction
  • Expansion bus interface
  • EEPROM interface for configuration
  • Data read/write burst operation
  • Global interrupt status register for all four UARTs
  • Up to 31.25 Mbps serial data rate
  • 16 multi-purpose inputs/outputs (MPIOs)
  • 16-bit general purpose timer/counter
  • Sleep mode with wake-up Indicator
  • Four independent UART channels controlled with
    • 16550 compatible register Set
    • 256-byte TX and RX FIFOs
    • Programmable TX and RX Trigger Levels
    • TX/RX FIFO Level Counters
    • Fractional baud rate generator
    • Automatic RTS/CTS or DTR/DSR hardware flow control with programmable hysteresis
    • Automatic Xon/Xoff software flow control
    • RS-485 half duplex direction control output with programmable turn-around delay
    • Multi-drop with Auto Address Detection
    • Infrared (IrDA 11) data encoder/decoder
  • Software compatible to XR17C15x, XR17D15x, XR17V25x PCI UARTs
  • Download Software Drivers

  • Next generation Point-of-Sale Systems
  • Remote Access Servers
  • Storage Network Management
  • Factory Automation and Process Control
  • Multi-port RS-232/RS-422/RS-485 Cards

Documentation & Design Tools

Type Title Version Date File Size
Data Sheets XR17V354 High Performance Quad PCI-Express UART 1.0.5 August 2018 3.8 MB
Application Notes DAN-190, MaxLinear UARTs in RS-485 Applications R01 July 2023 2.4 MB
Application Notes AN-225, Installing and Testing a PCI/PCIe UART Serial Port Using a Custom MaxLinear Driver in Linux 1B July 2018 427.1 KB
Application Notes AN 209 - Windows & Linux API interface code for PCI/PCIe UARTs’ drivers December 2011 199.5 KB
Application Notes AN-204, UART Sleep Mode 1.0.0 June 2010 515.8 KB
Application Notes AN-206, EEPROM Programming for PCIe UARTs 1.0.0 June 2010 183.2 KB
User Guides & Manuals XR17V35x MPIO Tool User Manual R00 March 2024 3.3 MB
User Guides & Manuals XR17V35x PCIe UARTs Design Guide 00 April 2020 2.3 MB
User Guides & Manuals XR17V358/354 Evaluation Board User's Manual R00 November 2018 19.9 MB
User Guides & Manuals PCI/PCIe EEPROM Programming Utility User Manual 1.0.0 November 2010 262.5 KB
Software: GUIs & Utilities XR17V35x MPIO Test Tool 1.0.0.0 March 2024 1.4 MB
Software: GUIs & Utilities PCIe "Super GUI" 1009 September 2018 1.8 MB
Software: GUIs & Utilities XR17V35x Windows EEPROM Programming Utility 1.0 July 2017 1.7 MB
Software: GUIs & Utilities XR17V35x Linux EEPROM Programming Utility 1.0.0 April 2013 161.7 KB
Errata XR17V35X Errata R01 July 2022 2.3 MB
Product Flyers High Performance Dual/Quad/Octal PCI Express UARTs November 2009 257.7 KB
Product Brochures Interface Brochure November 2023 3.7 MB
Software: Drivers Windows 10 5.5.0.0 September 2020 319.1 KB
Software: Drivers Linux 2.6.32 and newer 2.6.0.0 August 2019 20.2 KB
Software: Drivers Windows XP, Vista, 7, 8, 8.1 5.3.0.0 September 2015 275.2 KB
Software: Drivers Linux 2.6.16 1.0.0 April 2010 13.3 KB
Software: Drivers Linux 2.6.31 1.0.0 February 2010 12.7 KB
Software: Drivers Linux 2.6.27 1.0.0 November 2009 12.7 KB
Schematics & Design Files XR17V358IB/SP339 E8 Evaluation Board BRD, RSN Files REV 40 June 2016 1.6 MB
Schematics & Design Files Schematic 4.0 January 2016 296.6 KB
Simulation Models
Package Type Vcc Temp Mode Version File
FPBGA 3.3V Industrial Enable Buck_Regulator 3
FPBGA 3.3V Industrial Shut down Buck_Regulator 3
Package Type File
fpBGA-176
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Quality & RoHS

Part Number RoHS | Exempt RoHS Halogen Free REACH TSCA MSL Rating / Peak Reflow Package
XR17V354IB176-F N Y Y Y Y L4 / 245ᵒC L-fpBGA176

Click on the links above to download the Certificate of Non-Use of Hazardous Substances.

Additional Quality Documentation may be available, please Contact Support.

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status Buy Now Order Samples
XR17V354IB176-F L-fpBGA176 -40 85 Active Order
XR17V354/SP339-0A-EB Board Active
XR17V354/SP339-E4-EB Board Active
XR17V354/SP339-E8-EB Board Active

Part Status Legend
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.

Packaging

Pkg Code Details Quantities Dimensions PDF
L-fpBGA176
  • JEDEC Reference: MO-205
  • MSL Pb-Free: L4 @ 245ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 31.6ºC/W
  • Bulk Pack Style: Tray
  • Quantity per Bulk Pack: 160
  • Quantity per Reel: n/a
  • Quantity per Tube: n/a
  • Quantity per Tray: 160
  • Reel Size (Dia. x Width x Pitch): n/a
  • Tape & Reel Unit Orientation: n/a
  • Dimensions: mm
  • Length: 13.00
  • Width: 13.00
  • Thickness: 1.5
  • Lead Pitch: 0.80

Notifications

Distribution Date Description File
01/25/2022 MaxLinear has qualified Signetics, Korea, as an alternate assembly site for the products listed above. There is no change to datasheet form, fit, function.
07/18/2014 Material Change. UTAC qualification to use mold compound KSG1250LKDS, in addition to current qualified mold compound KMC2520AL.
07/14/2014 Material Change. UTAC qualification to use mold compound KEG1250LKDS, in addition to current qualified mold compound KMC2520AL.

FAQs & Support

Search our list of FAQs for answers to common technical questions.
For material content, environmental, quality and reliability questions review the Quality tab or visit our Quality page.
For ordering information and general customer service visit our Contact Us page.

Submit a Technical Support Question As a New Question

For some UARTs, Microsoft certified drivers are available for Windows Operating System and can be downloaded via Windows Update. These drivers and others, including for Linux and other Operating Systems can be found by visiting https://www.exar.com/design-tools/software-drivers Please note Software Driver Use Terms.

 

 
You can also get to this link by going to the exar.com website, clicking on Support (in black bar near top of page), then click on Design Tools, then under Evaluation Hardware and Software (towards right of page) click on Software Drivers.
 
 

Click on the version link under Driver Version of the desired type of UART, part number and operating system. A zip file is downloaded which contains a ReadMe file with instructions.

Links to datasheets and product family pages are in the software driver table for easy reference. 

The XR17Cxxx, XR17Dxxx, and XR17Vxxx are all UARTs but have the following basic differences:

  • PCI UARTs
    • XR17Cxxx – 5V supply, up to 33MHz clock input
    • XR17Dxxx – 5V or 3.3V supply, up to 33MHz clock input
    • XR17V2xx – 3.3V supply, up to 66MHz clock input
  • PCIe UARTs
    • XR17V3xx – 3.3V supply, up to 125MHz clock input

Yes, however, you will need to use a PCI-PCI bridge.

The schematics for our evaluation boards are available for download from https://www.exar.com/technical-documentation?doctypeid=34

No, it is not required. If an external EEPROM is not detected, the PCI UARTs will use Exar's default Vendor and Device ID. However, we do recommend that you use an EEPROM with your own Vendor and Device IDs.

You will need to be a member of PCI-SIG. You can find information for becoming a member at www.pcisig.com.

LSR bit-6 is a superset of LSR bit-5. The transmitter consists of a TX FIFO (or THR only when FIFOs are not enabled) and a Transmit Shift Register (TSR). When LSR bit-5 is set, it indicates that the TX FIFO (or THR) is empty, however there may be data in the TSR. When LSR bit-6 is set, it indicates that the transmitter (TX FIFO + TSR) is completely empty.

You can tell by reading LSR bit-5 or bit-6. If they are '0', then the transmit interrupt was generated by the trigger level. If they are '1', then the transmit interrupt was generated by the TX FIFO becoming empty. For enhanced UARTs, you can just read the FIFO level counters.

An RX Data Ready interrupt is generated when the number of bytes in the RX FIFO has reached the RX trigger level. An RX Data Timeout interrupt is generated when the RX input has been idle for 4 character + 12 bits time.

For some UARTs, the RX Data Timeout interrupt has a higher priority and in others, the RX Data Ready interrupt has a higher priority. See the interrupt priority section of the datasheet.

The UART requires a clock and a valid baud rate in order to transmit and receive data. Check that there is a clock signal on the XTAL1 input pin. Also, valid divisors need to be written into the DLL and DLM registers. Most UARTs have random (invalid) values upon power-up.

For most UARTs, the interrupt is generated when the data is ready to be read from the RX FIFO. The are some UARTs that generate the interrupt when the character with the error is received. There are some UARTs that have a register bit to select whether the LSR interrupt is generated immediately or delayed until it is ready to be read.

The UART will enter the sleep mode if the following conditions have been satisfied for all channels:
 
-Sleep Mode is enabled
-No interrupts are pending
-TX and RX FIFOs are empty
-RX input pin is idling HIGH (LOW in IR mode)
-Valid values in DLL and DLM registers
-Modem input pins are idle (MSR bits 3-0=0x0)
 
See AN204, UART Sleep Mode for more information on UART Sleep Mode

The UART will wake-up from sleep mode by any of the following conditions on any channel:
 
-Sleep mode is disabled
-Interrupt is generated
-Data is written into THR
-There is activity on the RX input pin
-There is activity on the modem input pins
 
If the sleep mode is still enabled and all wake-up conditions have been cleared, it will return to the sleep mode.
 
See AN204, UART Sleep Mode for more information on UART Sleep Mode 

For any UART that has the wake-up indicator interrupt, an interrupt will be generated when the UART wakes up even if no other interrupts are enabled.
 
See AN204, UART Sleep Mode for more information on UART Sleep Mode 

No, Auto RTS and Auto CTS are independent. Auto RTS is toggled by the UART receiver. Auto CTS is monitored by the UART Transmitter.

No, Auto RTS and Auto CTS will work normally without the interrupts enabled.

No, software flow control characters are not loaded into the RX FIFO.

Since 2-character software flow control requires that 2 consecutive flow control characters match before data transmission is stopped or resumes, there is less of a chance that data transmission is stopped because one data byte matched a control character.

Auto RS485 Half-Duplex Control feature overrides the Auto RTS flow control feature if both features use the RTS# output pin. Both features can only be used simultaneously if the Auto RS485 control output is not the RTS# output. For some UARTs, the Auto RS485 control output is not the RTS# output.

The polarity of the RS485 control output varies from one UART to another. For some UARTs, an inverter may be required. Some of the newer UARTs have register bits that can change that polarity of the RS485 control output.

In the normal mode, the TX interrupt is generated when the TX FIFO is empty, and there may still be data in the Transmit Shift Register. In the RS485 mode, the TX interrupt is generated when the TX FIFO and the TSR register are both empty.

It is recommended that the FIFO counters at the Scratchpad Register location be used. When transmitting or receiving data, writing to the LCR register could result in transmit and/or receive data errors.

Due to the dynamic nature of the FIFO counters, it is recommended that the FIFO counter registers be read until consecutive reads return the same value.

All of the UARTs that have the IR mode supports up to 115.2Kbps as specified in IrDA 1.0. The newer I2C/SPI UARTs can support up to 1.152Mbps as specified in IrDA 1.1.

Yes, if you are using a UART with a fractional baud rate generator. This provides a divisor feature with a granularity of 1/16, allowing for any baud rate to be generated by any clock frequency, standard or non-standard. Click on the parametric search button of the product family page and find the Fractional Baud Rate Generator column which tells which products have this feature.

Find the product page of the part that you want to get an evaluation board for and click on Parts & Purchasing. Example:

 

Find the icons under Buy Now or Order Samples:

 
 

Click on the Buy Now icon and see who has stock and click on the Buy button:

 
 
 

Alternatively, you can click on the Order Samples

 
 

If the icons are missing, then contact Customer Support.

The -F suffix indicates ROHS / Green compliance:
https://www.exar.com/quality-assurance-and-reliability/lead-free-program

Visit the product page for the part you are interested in.  The part's status is listed in the Parts & Purchasing section.  You can also view Product Lifecycle and Obsolescence Information including PDNs (Product Discontinuation Notifications).
 
To visit a product page, type the part into the search window on the top of the MaxLinear website.
 
In this example, we searched for XRA1201.  Visit the product page by clicking the part number or visit the orderable parts list by clicking "Orderable Parts". 
 
 
 

 

  

The Parts & Purchasing section of the product page shows the Status of all orderable part numbers for that product.  Click Show obsolete parts, to see all EOL or OBS products.

 
 
 

 

The XR17V35x device driver is dependent on the Generic multi-function driver being built into the Windows Embedded image. This driver is included by default in the desktop version of Windows, but not in the embedded versions.

The instructions for adding the Multi-function Driver are described by Microsoft:
https://msdn.microsoft.com/en-US/library/ff794057(v=winembedded.60).aspx

1. Native drivers: Native drivers may be found in all major OS such as Windows, Linux, and Max OSX. Typically these drivers will be automatically loaded. In some cases, these are basic drivers and may have limitations on advanced device functionality, however. USB HID, Hub and CDC-ACM drivers are examples of native drivers. The CDC-ACM driver be used with our CDC-ACM class USB UARTs, but has limited functionality.

 

2. MaxLinear custom drivers: MaxLinear custom drivers may be used to support additional functionality in MaxLinear devices. For example, the MaxLinear custom driver for USB UARTs overcomes the limitations of the native CDC-ACM driver. See https://www.exar.com/design-tools/software-drivers for a list of and access to the drivers that we currently have. In some cases, the MaxLinear driver can also be customized, or source code can be provided after executing a Software License Agreement.

It depends on the baud rate. For example, for a start bit, 8 data bits, no stop bit and 1 stop bit, the maximum baud rate deviation is 4.76%. For more information, see https://www.exar.com/appnote/dan108.pdf

See Application Note AN-225 https://www.exar.com/appnote/an-225.pdf

Most UARTs use RTS#, however in addition to using the RTS# output as the Auto RS485 control output, the XR17V352/354/358 can use the DTR# output as the Auto RS485 control output.

The EEPROM needs to have the PCI Vendor ID and Device ID, Subvendor ID and Subsystem Device ID. For more details, see DAN112 https://www.exar.com/appnote/dan112v100.pdf.

Please check that all the following conditions are satisfied first.

 

  • no interrupts pending (ISR bit-0 = 1)
  • modem inputs are not toggling (MSR bits 0-3 = 0)
  • RX input pin is idling HIGH • divisor (the value in DLL register) is non-zero
  • TX and RX FIFOs are empty

 

Be sure sleep mode bit has been set to 1. If there are multiple UART channels, the sleep conditions must be true for all channels.

 

See more on Sleep Mode in AN204 UART Sleep Mode.

Yes. Note: some devices do have powersave mode. If UART goes into powersave mode, then the registers are not accessible.

 

See more on Sleep Mode in AN204 UART Sleep Mode.

Read LSR register to check whether the UART receives the data or not.

 

  • If LSR value is 0x60, it means that either UART receiver FIFO doesn’t receive the data or the data in receiver FIFO has been read out before the read of LSR.
  • If LSR value is 0x00, it means data is still in the THR (clock doesn’t oscillate to transmit data).
  • If LSR value is 0xFF, it means either UART is in powersave mode or UART is powered off. For those devices with powersave mode, be sure that UARTS are not in powersave mode.

 

 

See more on Sleep Mode in AN204 UART Sleep Mode.

Although the MPIO driver and the first COM port of the PCIe UART share the same memory allocation, the resource conflict is not an issue because the MPIO driver and the COM port driver do not access any of the same register addresses. Note that, with this "memory conflict" warning message, the driver has passed Windows WHQL certification testing.
 
 

Videos

MxL UARTs Auto RS-485 Direction Control

This video describes how the automatic RS-485 half-duplex direction control feature in MaxLinear UARTs reduces driver development and frees up CPU/MCU loading. This feature eliminates the need to monitor the status of the UART’s transmit shift register and automatically switches MaxLinear RS-485 transceivers from the transmit mode to the receive mode. This video summarizes the content in application note DAN-190.