XR21B1420IL28-0A-EVB

XR21B1420IL28-0A-EVB Evaluation Board User’s Manual Introduction This user’s manual is for the XR21B1420IL24-0A-EVB evaluation board. The XR21B1420IL24-F shares a common evaluation board with the XR21B1421IL28-F and XR21B1421IL24-F. The main difference between the XR21B1420 and the XR21B1421 is that the XR21B1421 is an HID USB UART. The XR21B1420 is a USB CDC-ACM/Custom Vendor Request device. The only USB UART device installed on the XR21B1420IL24-0A-EVB evaluation board is the XR21B1420IL24-F. Table 1: Evaluation Board Ordering Part Numbers Device Ordering Part Number Evaluation Board Ordering Part Number Device Package Device Location XR21B1421IL24-F XR21B1421IL24-0A-EVB 24-pin QFN U3 XR21B1421IL28-F XR21B1421IL28-0A-EVB 28-pin QFN U5 XR21B1420IL28-F XR21B1420IL28-0A-EVB 28-pin QFN U4 Evaluation Board Overview A block diagram of the evaluation board is shown in Figure 1 below. USB Connector SP338 SP339 XR21B1420 DB9 Connector Figure 1: Evaluation Board Block Diagram In addition to the XR21B1420IL28-F, there is an Exar SP339 Multiprotocol transceiver on this evaluation board. The SP339 can be configured for Loopback, RS-232, Half-Duplex RS-485 or Full-Duplex RS-485/422 Modes. The default setting when shipped from the factory is RS-232 mode. Figure 2 and Figure 3 on the next page show the top view and bottom view of the evaluation board with all of the components, connectors and headers labeled. © 2020 MaxLinear, Inc. 1/6 maxlinear.com/XR21B1420 Rev 1B XR21B1420IL28-0A-EVB Figure 2: Top View of Evaluation Board Figure 3: Bottom View of Evaluation Board © 2020 MaxLinear, Inc. 2/6 maxlinear.com/XR21B1420 Rev 1B XR21B1420IL28-0A-EVB Hardware Configurations This sections describes the default settings when shipped from the factory and what jumper setting changes are required when changing modes. XR21B1420 Power Configurations When shipped from the factory, the XR21B1420 is configured for bus-powered mode and uses the 5V from the USB VBUS pin. The default jumper settings are: Table 2: Default Jumper Settings Jumper Setting Description J10 - 1 & 2 Connects 5V from VBUS to VCC_REG (pin 7). A regulated 3.3V output will be available on VCC (pin 6). J11 J13 - 2 & 3 J19 Not installed. Connects all pull-up resistors to 3.3V (+VCC_OUT = +VCC). Not installed. If not using the 5V from VBUS, an external 3.3V can be supplied to the VCC_REG pin. For testing purposes, there is an Exar SP6260 regulator on board that can be used. The required jumper settings for 3.3V operation are as follows: Table 3: Jumper Settings for 3.3V Operation Jumper Setting Description J10 - 2 & 3 Connects 3.3V from SP6260 to VCC_REG (pin 7). 3.3V will also need to be supplied to VCC via J19. J11 Not installed. J13 - 2 & 3 Connects all pull-up resistors to 3.3V (+VCC_OUT = +VCC). J19 - 1 & 2 Connects the regulated 3.3V from the SP6260 to the VCC pin of the XR21B1420. GPIO Configurations GPIO8/TXT When shipped from the factory, the GPIO8/TXT pin is connected to the LED. The default configuration of this pin is the TXT function. Table 4: Default Jumper Setting for GPIO8/TXT Jumper Setting J15 - 2 & 3 Description GPIO8/TXT connected to LED D1. LED D1 toggles when data is transmitting. Changing the header to J15 1&2 and adding a jumper on J16 3&4 will allow the GPIO8/TXT pin to control the MODE1 pin of the SP338/SP339 transceiver. © 2020 MaxLinear, Inc. 3/6 maxlinear.com/XR21B1420 Rev 1B XR21B1420IL28-0A-EVB GPIO9/RXT When shipped from the factory, the GPIO9/RXT pin is connected to the LED. The default configuration of this pin is the RXT function. Table 5: Default Jumper Setting for GPIO9/RXT Jumper Setting J17 - 2 & 3 Description GPIO9/RXT connected to LED D2. LED D2 toggles when data is received. Changing the header to J17 1&2 and adding a jumper on J16 5&6 will allow the GPIO5/RXT pin to control the MODE2 pin of the SP338 transceiver (this is a ’NC’ on the SP339). GPIO0/RI#/RWK# When shipped from the factory, the GPIO0/RI#/RWK# pin is connected to the push-button switch (SW1). Table 6: Default Jumper Setting for GPIO0/RI#/RWK# Jumper Setting J12 - 1 & 2 Description GPIO0/RI#/RWK# connected to SW1. Can be used for remote wake-up. Changing the header to J12 2&3 will connect the GPIO0/RI#/RWK# pin to the SP338/SP339 transceiver. GPIO2/DSR# By default, the GPIO2/DSR# pin is a GPIO input for the XR21B1420. When shipped from the factory, J20 is installed. The GPIO2/DSR# pin can be configured as a GPIO output using the GPIO control registers. See datasheet for complete details. SP338/SP339 Mode Selection When shipped from the factory, the SP338/SP339 are configured in the RS-232 mode. This is achieved with a combination of J18 and J4. J18 pins 2, 4 and 6 go to MODE0, MODE1 and MODE2, respectively. The SP338/SP339 have weak internal pull-down resistors. Table 7 shows the SP338/SP339 MODE pin configurations for the RS-232 mode. Table 7: SP339 RS-232 Mode Configurations Mode Configuration MODE0 1 MODE1 0 MODE2 0 For the RS-232 mode, there is a jumper from J18 pin 2 to J4 pin 1. Refer to the table in the schematic or the SP339 datasheet for more details of the different configurations. The SP338/339 transceiver is enabled with a jumper from J18 pin 8 to J4 pin 4. Half-duplex, Full-Duplex and Mixed Duplex RS-485/422 modes In the RS-485 half-duplex, full-duplex and mixed duplex modes, the DIR1 pin of the SP338/SP339 enables or disables the RS-485/422 line drivers. The DIR1 pin can be controlled by the XR21B1420 using the GPIO3/RS485 or GPIO1/RTS#/ RS485 output pins. The GPIO7/RS845 or GPIO5/RTS#/RS485 pin can be selected via J21. © 2020 MaxLinear, Inc. 4/6 maxlinear.com/XR21B1420 Rev 1B XR21B1420IL28-0A-EVB Software and Technical Support Visit www.maxliner.com/XR21B1420 or www.maxlinear.com/XR21B1421 to download documentation and design tools including software, software drivers, evaluation board schematics, and evaluation board design files. Visit www.maxlinear.com/support/contact-us to search for regional contacts, knowledge-base articles, and submit new support requests. © 2020 MaxLinear, Inc. 5/6 maxlinear.com/XR21B1420 Rev 1B XR21B1420IL28-0A-EVB Revision History Revision 1A 1B Date Description August 2014 January 2020 Initial release. Add MaxLinear logo and edit "Software and Technical Support" section. Corporate Headquarters: 5966 La Place Court Suite 100 Carlsbad, CA 92008 Tel.:+1 (760) 692-0711 Fax: +1 (760) 444-8598 www.maxlinear.com The content of this document is furnished for informational use only, is subject to change without notice, and should not be construed as a commitment by MaxLinear, Inc. MaxLinear, Inc. assumes no responsibility or liability for any errors or inaccuracies that may appear in the informational content contained in this guide. Complying with all applicable copyright laws is the responsibility of the user. Without limiting the rights under copyright, no part of this document may be reproduced into, stored in, or introduced into a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise), or for any purpose, without the express written permission of MaxLinear, Inc. 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MaxLinear, the MaxLinear logo, and any MaxLinear trademarks, MxL, Full-Spectrum Capture, FSC, G.now, AirPHY and the MaxLinear logo are all on the products sold, are all trademarks of MaxLinear, Inc. or one of MaxLinear’s subsidiaries in the U.S.A. and other countries. All rights reserved. Other company trademarks and product names appearing herein are the property of their respective owners. © 2020 MaxLinear, Inc. All rights reserved 6/6 maxlinear.com/XR21B1420 Rev 1B