XR28V384

3.3V Quad LPC UART with 128-Byte FIFO
Data Sheet

Description

The XR28V384 (V384) is a quad Universal Asynchronous Receiver and Transmitter (UART) for the Intel Low Pin Count (LPC) bus interface. This device can replace or supplement a Super I/O device to add additional serial ports to the system.

The V384 UARTs support any 16-bit I/O address supported by the system. The register set is based on the industry standard 16550 UART, so the V384 operates with standard serial port drivers without requiring a custom driver to be installed.

The 128 byte Transmit and Receive FIFOs reduce CPU overhead and minimize the chance of buffer overflow and data loss. In addition to the 16550 UART registers, there are also Configuration register set where enhanced features such as the 9-bit (multidrop) mode, IrDA mode and the Watchdog Timer can be enabled.

The V384 is available in a 48-pin TQFP package.

Features

  • 128 Byte Transmit and Receive FIFO
  • Compliant to LPC 1.1 Specifications
  • -40°C to +85°C Industrial Temp Operation
  • Watchdog Timer with WDTOUT# signal
  • 4 independent UART channels
    • Programmable I/O mapped base addresses
    • Data rates up to 3 Mbps
    • Selectable RX FIFO interrupt trigger levels
    • Auto RS-485 Half-Duplex Control mode
    • Programmable character lengths (5, 6, 7, 8) with even, odd, or no parity
    • IrDA mode and separate IRTXA# and IRRXA# pins for the first UART channel
    • 9-bit (Multidrop) mode
  • External 24MHz/48MHz clock
  • Single 3.3V Supply Voltage ( ± 10%)
  • 5V tolerant inputs
  • 48-TQFP package (7mm x 7mm)

Application

  • Industrial and Embedded PCs
  • Factory Automation and Process Controls
  • Network Routers
  • System Board Designs

Design Tools

Packaging

Pkg Code Details Quantities Dimensions PDF
TQFP48
  • JEDEC Reference: MO-026
  • MSL Pb-Free: L3 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 59.0ºC/W
  • Bulk Pack Style: Tray
  • Quantity per Bulk Pack: 250
  • Quantity per Reel: 1500
  • Quantity per Tube: n/a
  • Quantity per Tray: 250
  • Reel Size (Dia. x Width x Pitch): 330 x 16 x 12
  • Tape & Reel Unit Orientation: Quadrant 2
  • Dimensions: mm
  • Length: 7.0
  • Width: 7.0
  • Thickness: 1.2
  • Lead Pitch: 0.5

Parts & Purchasing

Part Number Pkg Code RoHS Min Temp Max Temp Status Buy Now Order Samples
XR28V384IM48-F TQFP48 -40 85 Active Order
XR28V384IM48TR-F TQFP48 -40 85 Active Order
XR28V384IM48-0A-EB Board Active
Show obsolete parts
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.

Quality Documents

Additional Quality Documentation may be available, please contact customersupport@maxlinear.com.
Distribution Date Description File
02/27/2017 Qualification of alternate assembly subcon, ANST.

Frequently Asked Questions

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.

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.

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.

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.

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

The best way to determine this is to go to maxlinear.com and type the part into the search function. At or near the top of the results you should see something that looks like:
 
 
 

In this example, we looked for XRA1201. Click on part number header or on the link at the bottom of the result.  This brings you to the product page. For example:

 
 
 

Click on Parts & Purchasing, highlighted with the blue arrow above. The screen changes to:

 
 
 

Notice the status column and the “Show obsolete parts” link.  A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers, the legend still present:

 
 
 

Another method to find out if a part is OBS or EOL is to click on SUPPORT at the top:

 
 
 

And then Product Change Notifications:

 
  
 

Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:

 
 
 

If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.

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