UM0212 STMICROELECTRONICS | Alldatasheet
Document overview
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Technical content
Datasheet sections
- 1 STOTG04 demonstration board hardware
- 1.1 STOTG04 power requirements
- 1.2 Connecting to a PC
- 1.3 Jumper assignments
- 1.4 Connector assignments
- 1.4.1 CON3 pin
- 1.5 Reset switch (SW1)
- 2 USB OTG demonstration software
- 2.1 Launching the software
- 2.2 PC-to-demonstration board communication
- 2.3 STOTG04 registers
it possible to test the STOTG04 transceiver while it is connected to the USB OTG controller. phones, digital cameras, printers and PDAs). monitor the transceiver’s internal registers. Figure 1. STOTG04 demonstration board
1 STOTG04 demonstration board hardware
The demonstration board consists of six main parts (see Figure 2 and Figure 3).
- Power supply pins (VBAT and VIF)
- Level shifters
- The STOTG04 full-speed transceiver
- Configuration jumpers
- A USB OTG controller connector
- A reset switch (see Section 1.5). The STOTG04 needs two types of power supply voltages to function (see Section 1.1). The battery supply voltage (VBAT) supplies power to the analog functions, and the digital interface voltage (VIF) supplies power to the digital interface. These supply voltages are connected to the demonstration board through the power pins. The board can also be controlled by a PC serial port (see Section 1.2). The RS-232C PC signal levels are converted to I2C levels by the level shifter block. The jumpers allow users to test and measure the STOTG04 characteristics without a USB OTG controller (see Section 1.3). The USB OTG controller header connector enables the user to connect a USB OTG controller (see CON3 pin) or any digital control system to the demonstration board. USB or USB OTG devices can be connected via the mini-AB connector (see Appendix A: STOTG04 demonstration board schematics).
Figure 2. STOTG04 demonstration board block diagram
Figure 3. Assembled demonstration board PCB
Figure 4. Demonstration board layout
1.1 STOTG04 power requirements
- VIF = 1.6 V to 3.6 V (VIF = 1.8 V, typ)
- VBAT = 2.7 V to 5.5 V (VBAT = 3.3 V, typ). The demonstration board was designed for these same voltage ranges. However, the board does not contain any voltage regulators, so if only one common supply voltage is used, the following range is recommended: V COMMON = 2.7 V to 3.6 V Note: Jumper J7 connecting the V BAT and VIF power supply pins has to be shorted (see Table 1).
1.2 Connecting to a PC
demonstration board software (see Chapter 2).
1.3 Jumper assignments
Table 1. Demonstration board jumper assignments (1)
1.4 Connector assignments
1.4.1 CON3 pin
- DAT_VP
- SE0_VM
- RCV
- OE_TP_INT
- I2C bus, and
- other main signals used by most types of OTG controllers. Warning: The Q1 and Q3 transistor bases MUST be connected to GND BEFORE the demonstration board is connected to the USB OTG controller. The Q1 and Q3 bases are connected to the R1 and R3 resistors (see Appendix A: STOTG04 demonstration board schematics).
Table 2. Demonstration board connectors (1) Table 3. CON3 pin assignments
1 GND 8 SPEED
2 Not connected 9 VM
3 SCL (I2C clock signal) 10 OE_TP_INT
4 SDA (I2C data signal) 11 RVC
6 RESET 13 DAT_VP
7 SUSPEND 14 SE0_VM
USB OTG demonstration software UM0212
1.5 Reset switch (SW1)
The Reset switch (see Figure 3 and Figure 4) can be used to manually reset the STOTG04 hardware. The reset pulse can also be generated by the USB OTG controller via the CON3 RESET pin (see Table 3).
2 USB OTG demonstration software
The "USB OTG Demo" software controls the STOTG04 full-speed transceiver. The application requires a PC with at least one serial port, and any Windows® operating system. Note: This software has been tested on Windows XP . The software configures and monitors the STOTG04’s internal registers. It sends and receives I2C signals with RS-232C voltage levels via the serial port. The RS-232C PC signal levels are converted to the proper I2C signal levels by the demonstration board’s level shifter (see Chapter 1).
2.1 Launching the software
The USB OTG demonstration program does not require any installation. 1. Copy the "demo.exe" file to a destination folder or C:\\temp directory 2. Double-click on the "demo.exe" file to launch the PC-to-demonstration board interface window 3. Use the RS-232C cable to connect the board to the PC (or confirm this connection if it is already set-up) 4. Select the correct PC serial port in the interface window (for example COM1, COM2, COM3 or COM4) 5. Select the STOTG04 address in the interface window (for example 2Ch or 2Dh). The default address is "2Dh", which is equivalent to open jumper J6 (see Section 1.3: Jumper assignments) 6. Select the correct device version (STOTG04E or STOTG04ES) 7. Connect the correct supply voltage to the demonstration board.
2.2 PC-to-demonstration board communication
Communication is controlled by two programming buttons (see Figure 5, bottom-right):
- Read all
- Write all. These buttons enable READs or WRITEs to all of the STOTG04 registers, otherwise the program cannot communicate with the STOTG04. Note: For correct use of the application and to prevent any anomalous behavior, it is important to understand the STOTG04 registers as well as the READ/WRITE sequence of the USB OTG demonstration program when multiple registers are changing at the same time.
2.3 STOTG04 registers
The STOTG04 has four types of registers (see Figure 5).
- Control registers
- Interrupt registers (source, latch, and falling/rising edges)
- Information registers (vendor ID and product ID)
- STOTG04 device address (2Ch or 2Dh) registers. Having a general knowledge of the registers may prevent certain anomalies. For example, if the J1 jumper is shorted and the "TRANSP_EN" bit has been set by mistake, the STOTG04 stops I 2C communication with the board because it is now in "Transparent I2C" mode. The communication can be reinstated by opening J1. Knowing the READ and WRITE sequence is important for using the interrupt registers, especially when multiple registers are changing at the same time. In these cases, the interrupt’s "falling edge" and "rising edge" registers have the highest priority. For example, to monitor the VBUS_VLD interrupt (this is usually done when the charge pump is switched ON): 1. set the VBUS_VLD bit in the "rising edge" register and the VBUS_DRV bit in "Control Register2" 2. Click on the "Write All" button The register WRITE order (priority) is: – "Write [Rising Edge (VBUS_VLD)]" THEN – "Write [Control Register 2 (VBUS_DRV)]". The user should always monitor the "Status" field to see if READ or WRITE operations are successful. Note that the TRANSP_EN bit in the control register 1 and the 2V7_EN bit in the control register 3 are enabled only when the STOTG04E device version is selected. The "VendorID" and "ProductID" registers are read-only and provide the STOTG04’s identity. Note: See the STOTG04 USB OTG full-speed transceiver datasheet for details.
Figure 5. USB OTG demonstration user interface registers Note: These are STOTG04 register settings after the first "Read All" instruction.
Figure 6. STOTG04 demonstration board schematics
Table 4. STOTG04 bill of materials
Revision history
Table 5. Document revision history