USB2SER

Freescale Semiconductor Data Sheet: Advance Information Document Number: USB2SERDS Rev. 0, 05/2011 USB2SER USB2SER Data Sheet USB to UART Application Specific IC Introduction The USB2SER is a USB to UART bridge controller on a 5 x 5 mm lead free QFN24. It is a simple low cost solution to enable a USB for an embedded system with a UART port, reducing external component counts. It supports USB 2.0 fullspeed and TTL RS232 or RS485 UART with options for hardware flow control, Software Flow control (Xon-Xoff), even or odd parity, and stop bits configuration. Features • • • • • Single chip USB to UART Data Transfer (RS232 or RS485) USB specification 2.0 compliant, full speed (12 Mbps) User programmable custom baud rates from 300 bps to 115200 bps UART supports 8 bit data, 1 or 2 stop bits and odd, even or no parity RESUME signal to request a remote wake-up and SUSPEND output to indicate that the device is in suspended mode Integrated 3.3 V regulator for a USB IO Integrated Power-On-Reset circuit Integrated 2 MHz – 48 Mhz clock multiplier PLL Supports 2 MHz, 4 MHz, 6 MHz, 8 MHz, 12 MHz, and 16 MHz external crystals with automatic crystal frequency detection USB bulk data transfer modes for data communication 3 V to 5 V single supply operation UHCI / OHCI / EHCI host controller compatible • • • Hardware flow control (RTC / CTS) or Software Xon/Xoff flow control RS485_TXEN signal to support RS485 USB and UART activity pins to indicate communication activity and fail sequences 24-pin QFN Case 1897 Drivers support The USB2SER can act as a CDC standard device that eliminates the need for custom drivers for operation when the flow-control is not needed (only an INF file is required). For flow control support, COM emulator drivers are available for: • • • • Windows XP 32-bits and 64-bits versions Windows Vista 32-bits and 64-bits versions Windows 7 32-bits and 64-bits versions Linux Kernel 2.6.34 and higher • • • • Additionally to the drivers, a software configuration tool is provided to customize the Product ID, Vendor ID, Product strings, current consumption parameters and password protection option, to prevent further modifications to the device information. For driver installation and software go to: The GUI and Driver Installer at www.freescale.com/usb2ser. Package USB2SER comes in a compact 5 x 5 mm Pb free RoHS compliant QFN24. • • • • • • • Configurable USB VID, PID, and device description strings in the internal flash Configurable password to protect the device from additional parameter modifications Data formats supported 8 bits data, 1 and 2 stop bits Parity odd, even, no parity This document contains information on a product under development. Freescale reserves the right to change or discontinue this product without notice. © Freescale Semiconductor, Inc., 2011. All rights reserved. USB Compliant Device USB2SER is fully compliant with the USB 2.0 specification and has been given the USB-IF Test-ID 10006196   USB2SER Data Sheet, Rev. 0 2 Freescale Semiconductor Contents USB2SER Introduction.................................................................................................................... 1 Features ..................................................................................................................... 1 Drivers Support ......................................................................................................... 2 Package ..................................................................................................................... 2 USB Compliant Device ............................................................................................ 2 Pins and Connections.................................................................................................. 4 Block Diagram .......................................................................................................... 4 Device Pin Out .......................................................................................................... 5 Recommended System Connections.................................................................... 5 Signals Description .................................................................................................. 6 Power (VDD, VSS, VSSOSC, VUSB33) ...................................................................... 7 Reset and System Initialization .............................................................................. 7 VID and PID configuration ...................................................................................... 8 Functional Description ................................................................................................. 8 Crystal Frequency Auto-detection ......................................................................... 8 Operating errors ....................................................................................................... 9 RS232 Connections ................................................................................................. 9 UART Baud rates ..................................................................................................... 9 Flow Control Operation ......................................................................................... 11 Operation with commercial terminals for serial communication ..................... 11 Drivers and GUI .......................................................................................................... 10 Graphical User Interface for Product Configuration.......................................... 11 Windows Driver ...................................................................................................... 14 Linux Driver ............................................................................................................. 14 Appendix A - Electrical Characteristics ................................................................... 17 Parameter Classification ....................................................................................... 17 Absolute Maximum Ratings .................................................................................. 17 Thermal Characteristics ........................................................................................ 18 Electrostatic Discharge (ESD) Protection Characteristics ..................................20 DC Characteristics ................................................................................................. 20 Supply Current Characteristics ............................................................................ 21 Appendix B - Package information .......................................................................... 21 Appendix C – INF File ................................................................................................... USB2SER Data Sheet, Rev. 0 Freescale Semiconductor 3 Pins and Connections 1 1.1 Pins and Connections Block diagram Reset Suspend Resume System Control Reset Power Management User Flash 512 Bytes USB Module Endpoint RAM Full Speed USB Transceiver USBDP USBDN EXTAL XTAL Clock Generator Module USB2SER Engine VDD VSS System Voltage Regulator UART RX RAM UART TX RAM TXD VUSB33 USB 3.3 Voltage Regulator UART / RS485 RXD RTS CTS RS485 CTL Figure 1. Device block diagram 1.2 Device pin out Figure 2. USB2SER — 24-QFN Package USB2SER Data Sheet, Rev. 0 4 Freescale Semiconductor Pins and Connections 1.3 Recommended system connections Figure 3. System connections working at 5 V Figure 4. System connections working at 3 V 1 RC filter on RESET is recommended for EMC-sensitive applications. regulator output is used for RPUDP. RPUDP can optionally be disabled if using an external pullup resistor on USBDP. 2 RPUDP is shown for full-speed USB only. The diagram shows a configuration where the on-chip regulator and RPUDP are enabled. The voltage 3 VBUS is a 5.0 V supply from upstream port that can be used for USB operation. 4 USBDP and USBDN are powered by the 3.3 V regulator. 5 When using internal VUSB33 as supply, there needs to be an external cap. USB2SER Data Sheet, Rev. 0 Freescale Semiconductor 5 Pins and Connections 1.4 Signals description Table 1. Signal descriptions Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Pin Name /RESUME /RESET /SUSPEND NC USB_LED NC UART_LED RS485_TXEN RTS CTS VDD NC VSS USBDN USBDP VUSB33 VUSB33MON NC RXD TXD XTAL EXTAL VSS_OSC NC Description Pin to request a remote wake-up Reset pin Indicates when the device is in suspended mode No connect USB activity LED connection No connect UART Activity LED connection Transmitter control pin for RS485 transceiver UART request to send UART clear to send Supply voltage No connect 0 V ground input USB data minus signal USB data plus signal Bidirectional signal connected to the 3.3 V regulator USB Internal regulator monitor pin. Connect to VUSB33 No connect UART reception pin UART transmission pin XTAL crystal oscillator pin for Pierce oscillator EXTAL crystal oscillator pin for Pierce oscillator 0 V ground input for the oscillator reference No connect 1.5 Power (VDD, VSS, VSSOSC, VUSB33) The VDD and VSS are the primary power supply pins for the USB2SER. This voltage source supplies power to all the I/O buffer circuitry and to an internal voltage regulator. Typically, application systems have two separate capacitors across the power pins. A 10 µF tantalum capacitor which provides bulk charge storage for the overall system and a 0.1 µF ceramic bypass capacitor to suppress high-frequency noise is located as near as possible to the paired VDD and VSS power pins. The USB2SER has a VSSOSC pin. This pin must be connected to the system ground plane or to the primary VSS pin through a low-impedance connection. If using an external 3.3 V regulator as an input to VUSB33, the supply voltage, VDD, must not fall below the input voltage at the VUSB33 pin. If using the internal 3.3 V regulator, do not connect an external supply to the VUSB33 pin. In this case, VDD must fall between 3.9 V and 5.0 V for the internal 3.3 V regulator to operate correctly. The USB2SER uses the VUSB33MON pin to detect VDD used and configure the device accordingly. USB2SER Data Sheet, Rev. 0 6 Freescale Semiconductor Pins and Connections 1.6 • • • Reset and system initialization Power-on Reset (POR) External Reset Pin (RESET) Software update Reset (Soft Reset) The USB2SER has three reset sources: System startup from any reset source starts with the crystal frequency auto-detection that takes 48 ms. After this step, the device initializes the internal PLL to setup the internal clock to 48 MHz which will be used as the reference for the USB and UART to work properly. After reset from a source different than a POR, the VUSB33MON is configured to discharge the capacitors connected to the VUSB33 voltage when working from a 5V power supply; this adds a 40msec delay to the system startup to determine if the internal voltage regulator has to be enabled. RESET Is Reset a POR Wait for VUSB33 Capacitors discharge 550ms Crystal Autodetection PLL Init System Init 48msec System Ready Figure 5. Clock and system initialization 1.7 • • • • • • VID and PID configuration VID — 15A2 Hex PID — 005A Hex Power Descriptor Value for 100 mA Manufacturer string — FREESCALE SEMICONDUCTOR INC. Product string — USB TO SERIAL Serial number string — Version 1.0 The USB2SER includes the functionality to modify the VID, PID, Product Description Strings and Power Descriptor Value. The default parameters are: USB2SER Data Sheet, Rev. 0 Freescale Semiconductor 7 Functional Description Each USB peripheral requires a unique VID/PID combination. Vendor IDs are assigned by the USB-IF. It is possible to us the factory VID/PID combination, only if the Product strings are not modified. In case that the strings are changed, it is necessary to get a different VID/PID combination. Freescale, as a member of the USB-IF, owns a Vendor ID and manages a database of Product IDs to be used in association with the VID. If a customer of Freescale’s USB-enabled products is unable to procure their own VID, apply to use Freescale’s VID in association with an assigned PID. In case the device loses power in the middle of a descriptors configuration process, the default parameters will be loaded to ensure that the part remains functional in all cases. If this happens, the password to protect the device from further modifications will also be reset to the default value which is “FFFFFFFFFFFFFFFF” 2 Functional Description The USB2SER is a USB2.0 Full Speed (12Mb/s) to the UART (RS232 or RS485) converter. This device integrates an on-chip Full Speed USB 2.0 compatible transceiver, the USB serial interface engine, and an on-chip 3.3 V voltage regulator to a UART communication. 2.1 Crystal frequency auto-detection The USB2SER supports 2MHz, 4MHz, 6MHz, 8MHz, 12MH, and 16MHz external crystals connected in a Pierce Oscillator Configuration. Figure 6. Pierce Oscillator 2.2 • • Operating errors For a PLL issue (crystal outside the operating range) the gray sequence changes every 60 ms For a USB issue the sequence changes every 200 ms In case there is an error with the USB2SER, the device will generate a 2-bit gray sequence using the UART_LED and USB_LED. The following are the possible errors and the device expected behavior: 2.3 RS232 connections Figure shows the recommended connections to an RS232 transceiver. When interfacing to an RS485 transceiver, the RS485_TXEN controls the transmitter enable signal. USB2SER Data Sheet, Rev. 0 8 Freescale Semiconductor Functional Description Figure 7. Example schematic using an RS232 transceiver 2.4 UART Baud rates Baud rate is calculated by generating an internal divisor used to generate the clock for the UART communication module. The following calculation is used to estimate the real baud rate that will be generated by the device: 24 000 000 BaudRate = -------------------------------------------------------------------------------------------24 000 000  --------------------------------------------------------   16 Round  DesiredBaudrate  16 24 000 000 Round = -------------------------------------------------------------24 000 000  --------------------------------------------------------   DesiredBaudrate  16 Where is the closest integer resulting from the division. After reset the device is automatically configured to communicate at 115,200 bps which is the maximum allowed value. 2.5 Flow control operation The device works as a standard Communication Device Class (CDC); to add flow control options to this class, the drivers are installed in the operating system to enable this functionality. When working without any flow control option, it is possible to generate an overflow condition, if the USB host does not request for the data received through the serial interface fast enough. Using any flow control option (hardware or software) eliminates the overflow possibility. The following formula may be used to determine the amount of time without requesting data to generate the overflow condition: USB2SER Data Sheet, Rev. 0 Freescale Semiconductor 9 Drivers and GUI Overflow _ Timeout  Where: BitsPerByte * 96 BaudRate BitsPerByte — 11 for 2 stop bits or any parity option or 10 for 1 stop bit without parity 96 is the Serial buffer size in Bytes In case the USB host does not request for data before the time out expires and there is no flow control option selected, previously received data will be overwritten with the new received information. 2.6 Operation with commercial terminals for serial communication Standard terminals for UART communication may have some limitations in the type of data that may be sent/received or some protocol supports. Known limitations are: • • Binary option must be supported to communicate data that is not standard text Communication Protocols (that is, Z modem with Crash recovery, X modem, Y modem, Kermit, and so on) may include a protocol timeout that may not work in baud rates below 2400 bps When using a standard terminal (HyperTerminal or TeraTerm for example) you must, make sure that the proper configuration is selected to send the desired type of information. 3 Drivers and GUI The USB2SER can work with the standard Windows driver or with a custom driver for expanded functionality. The Microsoft Windows driver will enable a USB to COM port communication but without Hardware or Software Flow control features from the Host PC to the device. To use this approach, it is possible to copy contents from Appendix C and save it as a file with extension .inf. When the driver is requested the first time after connecting the device it is possible to select this INF file. Freescale custom drivers for communication allow using any standard terminal or customer software to enable or disable Hardware or Software flow control. The driver also comes with a set of functions to configure Maximum Current consumption through the USB port, Product Strings, Vendor ID and Product ID. Password protects these settings. If any of the product strings or VID/PID is changed, it is necessary to send the product for USB certification if the customer wants to use the USB logo. 3.1 Graphical user interface for product configuration The GUI provided with the USB2SER is intended to allow the modification of the Bus Power configuration, Vendor ID, Product ID and any of the manufacturer strings. This allows the customization of any product using this product. It is also possible to password protect the device configuration to avoid future modifications after a product release. USB2SER Data Sheet, Rev. 0 10 Freescale Semiconductor Drivers and GUI To configure any or all these settings, once the GUI is open, select the right COM port for the USB2SER. To Read the configuration of the USB2SER write the correct password on the current password field and click on the Read button (The Password must be 16 characters long, values allowed are 0–9 and A–F, default password is “FFFFFFFFFFFFFFFF”) USB2SER Data Sheet, Rev. 0 Freescale Semiconductor 11 Drivers and GUI You should now be able to see the configuration of the USB2SER: To change any or several parameters from current list, change the desired values and click the Change button. • • • • • For Maximum Current Consumption you can use a value between 20 and 500 and for definition of USB.org, this field only supports even values, value of 0 will cause to change the selection to Self Powered. For Vendor ID and Product ID values allowed are 0–9 and A–F For Manufacturer String, Product String and Serial Number Strings, any printable ASCII character is valid All the fields must have valid information to change the configuration of the USB2SER Bridge In case you need to change the current password, you will be able to by writing the new password in the New Password field, then click on the Change button to finish this step. USB2SER Data Sheet, Rev. 0 12 Freescale Semiconductor Drivers and GUI • Click the Read button with the new password in the Current Password field to confirm that USB2SER bridge setting has been updated according to the previous step. 3.2 Windows driver Windows driver comes with a product installer. To install it: Download the latest installer version from www.freescale.com/usb2ser. To install, double-click on the installation file. A startup window appears. On the opening window, follow the on-screen instructions Additional documentation is available for driver usage when developing custom applications in Windows. 3.3 1. 2. Linux driver Unpack the .tar file downloaded In the folder containing the un packed files, check for these four files: — cdc-freescale.c — cdc-freescale.h — Makefile — Install.sh Open a console and move to the previously mentioned folder. — Change current user to root. – $ sudo su – [sudo] password for user: Execute Install script passing as a parameter the name of the host distribution (all lower case). — Ubuntu – # ./Install.sh ubuntu — Fedora – # ./Install.sh fedora — Red Hat – # ./Install.sh redhat Move to CDC driver location. — # cd /lib/modules/$(uname -r)/kernel/drivers/usb/class/ Check for backup file. — # ls — cdc-acm2011.01.27-11.55.54.ko cdc-acm.ko cdc-wdm.ko usblp.ko usbtmc.ko To install the Linux driver follow these simple steps: 3. 4. To uninstall 1. 2. NOTE The backup name varies because it is created at install time merging the original file name plus the date-time. An example is shown in the upper text. 3. 4. Erase current CDC driver. — # rm cdc-acm.ko Rename backup file. — # mv cdc-acm2011.01.27-11.55.54.ko cdc-acm.ko USB2SER Data Sheet, Rev. 0 Freescale Semiconductor 13 Electrical Characteristics Appendix A Electrical Characteristics This chapter contains electrical and timing specifications. A.1 Parameter Classification The electrical parameters shown in this supplement are guaranteed by various methods. To give the customer a better understanding, the following classification is used and the parameters are tagged accordingly in the tables where appropriate: Table A-1. Parameter classifications P Those parameters are guaranteed during production testing on each individual device. C Those parameters are achieved by the design characterization by measuring a statistically relevant sample size across process variations. Those parameters are achieved by design characterization on a small sample size from T typical devices under typical conditions unless otherwise noted. All values shown in the typical column are within this category. D Those parameters are derived mainly from simulations. NOTE The above classifications are used in the column labeled C in applicable tables of this data sheet. A.2 Absolute Maximum Ratings Absolute maximum ratings are only stress ratings. Functional operation at maximum is not guaranteed. Stress beyond the limits specified in Table A-2 may affect the device reliability or cause permanent damage to the device. For functional operating conditions, refer to the remaining tables in this section. This device contains circuitry protecting against damage due to high static voltage or electrical fields. However, it is advised that normal precautions be taken to avoid application of any voltages higher than the maximum-rated voltages to this highimpedance circuit. Reliability of operation is enhanced if unused inputs are tied to an appropriate logic voltage level (for instance, either VSS or VDD). Table A-2. Absolute maximum ratings Rating Supply voltage Input voltage Symbol VDD Vin Value 2.7 to 5.5 –0.3 to VDD + 0.3 ± 25 mA –55 to 150 ｰ 150 ｰ C C Unit V V mA Instantaneous maximum current Single pin ID limit (applies to all port pins)1, 2, 3 Maximum current into VDD Storage temperature Maximum junction temperature IDD 120 Tstg TJ 1. Input must be current limited to the value specified. To determine the value of the required current-limiting resistor, calculate resistance values for positive (VDD) and negative (VSS) clamp voltages, then use the larger of the two resistance values. 2. All functional non-supply pins are internally clamped to VSS and VDD. USB2SER Data Sheet, Rev. 0 14 Freescale Semiconductor Electrical Characteristics 3. Power supply must maintain regulation within operating VDD range during instantaneous and operating maximum current conditions. If positive injection current (VIn > VDD) is greater than IDD, the injection current may flow out of VDD and can result in the external power supply going out of regulation. Ensure external VDD load will shunt current greater than maximum injection current. This will be the greatest risk when the MCU is not consuming power. Examples are: if no system clock is present, or if the clock rate is very low which reduces overall power consumption. A.3 Thermal Characteristics This section provides information about operating temperature range, power dissipation, and package thermal resistance. Power dissipation on I/O pins is usually small compared to the power dissipation in on-chip logic. It is user-determined rather than being controlled by the MCU design. To take PI/O into account in power calculations, determine the difference between actual pin voltage and VSS or VDD and multiply by the pin current for each I/O pin. Except in cases of unusually high pin current (heavy loads), the difference between pin voltage and VSS or VDD will be very small. Table A-3. Absolute maximum ratings Rating Operating temperature range (packaged) Thermal Resistance 1, 2, 3, 4 24-pin QFN 1s 2s2p JA TA Symbol Value TL to TH -40 to 85 Unit °C 92 33 ° C/W 1. Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance, mounting site (board) temperature, ambient temperature, air flow, power dissipation of other components on the board, and board thermal resistance 2. Junction to Ambient Natural Convection 3. 1s — Single layer board, one signal layer 4. 2s2p — Four layer board, 2 signal and 2 power layers The average chip-junction temperature (TJ) in × ° C can be obtained from: Tj = TA + P Where: TA — Ambient temperature,° C P Iq D JA D   JA Eqn. 1 JA — Package thermal resistance, junction-to-ambient,° C/W PD — Pint + PI/OPint = IDD × VDD, Watts — chip internal power PI/O — Power dissipation on input and output pins — user determined For most applications, PI/O