VS2000 PRELIMINARY VS2000 VS2000 - Headtracking Multichannel USB Audio Headphone IC / USB DAC Hardware Features • Low-power operation • Single input voltage: Internal voltage regulation for analog, digital, and I/O power • Operates with a single 12 MHz clock • Internal PLL clock multiplier • USB Full Speed hardware • I/O for user interface • High-quality on-chip stereo DAC with no phase error between channels • Stereo earphone driver capable of driving a 30 Ω load • Lead-free RoHS-compliant package (Green) Firmware Features • 5.1-channel USB Audio Device • Human Interface Device (HID) Buttons – Volume Decrement – Volume Increment – Pause – Play – Rewind – Fast Forward • Volume controls also work without HIDaware host • Four room effect levels selected with Effect Level Button • Tracking On / Tracking Off / Bypass modes selected with Power Button • Bass and treble controls through USB Audio Feature Unit • Advanced controls through separate software • SPI EEPROM boot for special applications • UART for debugging and special applications Version 0.3, 2007-09-05 Description VS2000 is a single-chip multichannel headtracking USB Audio IC with audio output to headphones. VS2000 contains a high-performance lowpower DSP core VS DSP4 , Full Speed USB port, general purpose I/O pins, SPI, UART, as well as a high-quality variable-sample-rate stereo DAC, and an earphone amplifier, and a common voltage buffer. When connected to USB, VS2000 firmware controls an ultrasound transmitter and reads ultrasound receivers to track the movement of the listener’s head. VS2000 then performs real-time spatial processing to the 5.1 audio channels to position each sound source correctly depending on the head movement. An application without headtracking and just with 5.1 audio is also possible. SPI EEPROM can be used to load code to customize the system. 1 VLSI VS2000 PRELIMINARY y Solution VS2000 CONTENTS Contents 1 Disclaimer 4 2 Definitions 4 3 Characteristics & Specifications 4 3.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.3 Analog Characteristics of Audio Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.4 Analog Characteristics of Regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.5 Power Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.6 Digital Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4 5 6 Packages and Pin Descriptions 7 4.1 Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.2 LQFP-48 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 VS2000 Functional Blocks 10 5.1 Regulator Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.2 Digital Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.3 Analog Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Firmware Operation 13 6.1 SPI Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.2 UART Boot/Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.3 Default Firmware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.3.1 15 Version 0.3, 2007-09-05 USB Audio Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 VLSI VS2000 PRELIMINARY y Solution 6.3.2 7 8 9 VS2000 LIST OF FIGURES USB Human Interface Device . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Example Application 17 7.1 19 Usage Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Document Version Changes 20 8.1 Version 0.3, 2007-09-05 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 8.2 Version 0.2, 2007-08-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 8.3 Version 0.1, 2007-06-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Contact Information 21 List of Figures 1 Pin Configuration, LQFP-48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 VS2000 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3 VS2000 Example Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4 VS2000 Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5 VS2000 Example Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Version 0.3, 2007-09-05 3 VLSI VS2000 PRELIMINARY y Solution 1 VS2000 1. DISCLAIMER Disclaimer This is a preliminary datasheet. All properties and figures are subject to change. 2 Definitions B Byte, 8 bits. b Bit. Ki “Kibi” = 210 = 1024 (IEC 60027-2). Mi “Mebi” = 220 = 1048576 (IEC 60027-2). VS DSP VLSI Solution’s DSP core. W Word. In VS DSP, instruction words are 32-bit and data words are 16-bit wide. 3 Characteristics & Specifications 3.1 Absolute Maximum Ratings Parameter Regulator input voltage Injected Current on Any Pin Voltage at Any Digital Input Operating Temperature Storage Temperature 1 Symbol VHIGH Min -0.3 -0.3 -40 -65 Max 4.0 ±50 IOVDD+0.31 +85 +150 Unit V mA V ◦C ◦C Must not exceed 3.6 V 3.2 Recommended Operating Conditions Parameter Ambient Operating Temperature Analog and Digital Ground 1 Regulator input voltage3 Input Clock Frequency Internal Clock Frequency Master Clock Duty Cycle Symbol AGND DGND VHIGH XTALI CLKI Min -40 AVDD+0.3 12 40 Typ 0.0 5.0 122 48 50 Max +85 5.25 48 60 Unit ◦C V V MHz MHz % 1 Must be connected together as close the device as possible for latch-up immunity. To be able to use USB, XTALI must be 12 MHz. 3 4.0 V is required for compliant USB level. 2 Version 0.3, 2007-09-05 4 VLSI VS2000 VS2000 PRELIMINARY3. CHARACTERISTICS & SPECIFICATIONS y Solution 3.3 Analog Characteristics of Audio Outputs Unless otherwise noted: AVDD=2.8V, CVDD=2.5V, IOVDD=3.3V, TA=-40..+85◦ C, XTALI=12 MHz, Internal Clock Multiplier 4.0×. DAC tested with full-scale output sinewave, measurement bandwidth 20..20000 Hz, analog output load: LEFT to CBUF 30Ω, RIGHT to CBUF 30Ω. Parameter DAC Resolution Total Harmonic Distortion Dynamic Range (DAC unmuted, A-weighted) S/N Ratio (full scale signal, no load) Interchannel Isolation (Cross Talk) Interchannel Isolation (Cross Talk), with GBUF Interchannel Gain Mismatch Frequency Response Full Scale Output Voltage (Peak-to-peak) Deviation from Linear Phase Analog Output Load Resistance Analog Output Load Capacitance CBUF disconnect current (short-circuit protection) Symbol Min THD IDR SNR Typ 18 Max 0.1 50 -0.5 -0.05 1.3 94 90 75 40 1.5 0.5 0.05 1.7 5 1 AOLR 30 1002 200 Unit bits % dB dB dB dB dB dB Vpp ◦ Ω pF mA 1 AOLR may be lower than Typical, but distortion performance may be compromised. Also, there is a maximum current that the internal regulators can provide. 2 CBUF must have external 10 Ω + 47 nF load, LEFT and RIGHT must have external 20 Ω + 10 nF load for stability. 3.4 Analog Characteristics of Regulators Parameter Continuous current, IOVDD Continuous current, CVDD Continuous current, AVDD Dropout voltages, 30 mA Line regulation, VHIGHmin . . . VHIGHmax Load regulation, 1 mA . . . 30 mA Absolute gain setting accuracy 1 Gain step setting accuracy 1 Symbol Min Typ Max 50 50 100 0.3 10 100 +150 +10 -150 -10 Unit mA mA mA V mV mV mV % Absolute level depends on RCAP voltage 3.5 Power Consumption Parameter Full operation in example application, Vbus = 5 V Version 0.3, 2007-09-05 Min Typ 75 Max Unit mA 5 VLSI VS2000 VS2000 PRELIMINARY3. CHARACTERISTICS & SPECIFICATIONS y Solution 3.6 Digital Characteristics Parameter High-Level Input Voltage Low-Level Input Voltage High-Level Output Voltage at IO = -2.0 mA Low-Level Output Voltage at IO = 2.0 mA Input Leakage Current Rise time of all output pins, load = 50 pF Version 0.3, 2007-09-05 Symbol Min 0.7×IOVDD -0.2 0.7×IOVDD -1.0 Typ Max IOVDD+0.31 0.3×IOVDD 0.3×IOVDD 1.0 50 Unit V V V V µA ns 6 VLSI VS2000 PRELIMINARY y Solution 4 4.1 VS2000 4. PACKAGES AND PIN DESCRIPTIONS Packages and Pin Descriptions Packages LPQFP-48 is lead (Pb) free and also RoHS compliant package. RoHS is a short name of Directive 2002/95/EC on the restriction of the use of certain hazardous substances in electrical and electronic equipment. 48 1 Figure 1: Pin Configuration, LQFP-48. LQFP-48 package dimensions are at http://www.vlsi.fi/ . Version 0.3, 2007-09-05 7 VLSI VS2000 PRELIMINARY y Solution 4.2 4. PACKAGES AND PIN DESCRIPTIONS LQFP-48 Pin Descriptions Pin Name XRESET GPIO0 0 GPIO0 1 GPIO0 2 GPIO0 3 DGND0 IOVDD1 TEST GPIO0 4 GPIO0 5 GPIO0 6 GPIO0 7 GPIO0 8 GPIO0 9 GPIO0 10 GPIO0 12 GPIO0 13 DGND1 IOVDD2 GPIO0 11 GPIO0 14 XCS / GPIO1 0 SCLK / GPIO1 1 SI / GPIO1 2 SO / GPIO1 3 TX / GPIO1 4 RX / GPIO1 5 XTALI XTALO IOVDD DGND2 CVDD VHIGH AVDD USBP USBN PWRBTN AGND0 AVDD1 RIGHT AGND1 AGND2 CBUF AVDD2 RCAP AVDD3 LEFT AGND3 Version 0.3, VS2000 2007-09-05 LQFP Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Pin Type DI DIO DIO DIO DIO DGND IOPWR DI DIO DIO DIO DIO DIO DIO DIO DIO DIO DGND IOPWR DIO DIO DIO DIO DIO DIO DIO DIO AI AO IOPWR DGND CPWR PWR APWR AIO AIO AIO APWR APWR AO APWR APWR AO APWR AIO APWR AO APWR Function Active low asynchronous reset, schmitt-trigger input General-purpose IO Port 0, bit 0 General-purpose IO Port 0, bit 1 General-purpose IO Port 0, bit 2 General-purpose IO Port 0, bit 3 Core & I/O ground I/O power supply Test mode input (active high), connect to DGND General-purpose IO Port 0, bit 4 General-purpose IO Port 0, bit 5 General-purpose IO Port 0, bit 6 General-purpose IO Port 0, bit 7 General-purpose IO Port 0, bit 8 General-purpose IO Port 0, bit 9 General-purpose IO Port 0, bit 10 General-purpose IO Port 0, bit 12 General-purpose IO Port 0, bit 13 Core & I/O ground I/O power supply General-purpose IO Port 0, bit 11 General-purpose IO Port 0, bit 14 SPI XCS / General-Purpose I/O Port 1, bit 0 SPI CLK / General-Purpose I/O Port 1, bit 1 SPI MISO / General-Purpose I/O Port 1, bit 2 SPI MOSI / General-Purpose I/O Port 1, bit 3 UART TX / General-Purpose I/O Port 1, bit 4 UART RX / General-Purpose I/O Port 1, bit 5 Crystal input Crystal output I/O power supply, Regulator output Core & I/O ground Core power supply, Regulator output Power supply, Regulator input Analog power supply, Regulator output USB differential + in / out, controllable 1.5kΩ pull-up USB differential - in / out Power button for Regulator startup (and Power Key) Analog ground Analog power supply Right channel output Analog ground Analog ground Common voltage buffer for headphones Analog power supply Filtering capacitance for reference Analog power supply Left channel output Analog ground 8 VLSI VS2000 PRELIMINARY y Solution VS2000 4. PACKAGES AND PIN DESCRIPTIONS Pin types: Type DI DO DIO AI AO Version 0.3, Description Digital input, CMOS Input Pad Digital output, CMOS Input Pad Digital input/output Analog input Analog output 2007-09-05 Type AIO APWR DGND CPWR IOPWR Description Analog input/output Analog power supply pin Core or I/O ground pin Core power supply pin I/O power supply pin 9 VLSI VS2000 PRELIMINARY y Solution 5 VS2000 5. VS2000 FUNCTIONAL BLOCKS VS2000 Functional Blocks LEFT RIGHT CBUF RCAP VHIGH PWRBTN Reference AVDD1 AVDD2 AVDD3 Stereo Earphone Driver Stereo DAC Common Voltage Driver Regulator Regulator Voltage Monitor Regulator USBP USPN XCS/GPIO1[0] SCLK/GPIO1[1] SI/GPIO1[2] SO/GPIO1[3] USB Serial Data/ Control Interface CVDD X RAM X ROM VSDSP4 processor UART Y RAM XTALO XTALI Clock Y ROM NAND Flash Interface/ General IO I RAM Control/ GPIO0[8...14] AVDD <1.6V reset RX/GPIO1[5] TX/GPIO1[4] Data/ GPIO0[0...7] IOVDD I ROM TEST XRESET IOVDD1 IOVDD2 Figure 2: VS2000 Block Diagram 5.1 Regulator Section The VHIGH pin in the regulator section is used as a common main power supply for voltage regulation. This input is connected to three internal regulators, which are activated when the PWRBTN pin is set high for about one millisecond, so that AVDD starts to rise and reaches about 1.5 V. After the PWRBTN has given this initial start current, the regulators reach their default voltages even if the PWRBTN is released. VHIGH must be sufficiently (about 0.3 V) above the highest regulated power (normally AVDD) so that regulation can be properly performed. The PWRBTN state can also be read by software, so it can be used as one of the user interface buttons. A power-on reset monitors the core voltage and asserts reset if CVDD drops below 1.6 V. It is also possible to force a reset by keeping PWRBTN pressed for longer than approximately 5.6 seconds. A watchdog counter and the XRESET pin can also generate a reset for the device. Resets do not cause the regulators to shut down, but they restore the default regulator voltages. After boot the firmware and user software can change the voltages. Return to power-off is possible only with active software control (VSDSP writes the regulator shutdown bit), or when VHIGH voltage is removed for a sufficiently long time. In the default firmware player the power button has to be pressed for 2 seconds to make the software powerdown the system and turn the regulators off. Version 0.3, 2007-09-05 10 VLSI VS2000 PRELIMINARY y Solution 5.2 VS2000 5. VS2000 FUNCTIONAL BLOCKS Digital Section Two of the regulators provide power supply for the digital section. IOVDD is used for the level-shifters of the digital I/O and crystal oscillator. The IOVDD regulator output must be connected to IOVDD1 and IOVDD2 input pins, because they are not connected internally. Proper bypass capacitors should also be used. After reset the I/O voltage is 1.8 V, and firmware raises it to 3.3 V. All other digital is powered from core voltage (CVDD). The core voltage is internally connected, and the CVDD pin should have a proper bypass capacitors. Clock The crystal amplifier uses a crystal connected to XTALI and XTALO. An external logic-level input clock can also be used. When VS2000 is used with USB, 12 MHz input clock must be used. An internal phase-locked loop (PLL) generates the internal clock by multiplying the input clock by 1.0×, 1.5×, . . . , 4.0×. In normal operating mode the clock is 4.0×12 MHz = 48 MHz. During USB suspend the PLL is off. XRESET disables clock buffer and puts the digital section into powerdown mode. VSDSP4 VSDSP4 is VLSI Solution’s proprietary digital signal processor with a 32-bit instruction word, two 16-bit data buses, and both 16-bit and 32/40-bit arithmetic. IROM, XROM, and YROM contain the firmware, including the default application. Most of the instruction RAM and some of the X and Y data RAM’s can be used to customize and extend the functionality. UART An asynchronous serial port is used for debugging and special applications. The default speed is 115200 bps. RX and TX pins can also be used for general-purpose I/O when the UART is not required. SPI A synchronous serial port peripheral is used for SPI EEPROM boot, and can be used to access other SPI peripherals (for example LCD or SED) by using another chip select. The SPI is only used for boot if the XCS pin has a high level after reset (pull-up resistor attached). These pins can also be used for general-purpose I/O when the SPI is not required. The firmware uses SPI pins SO and SCLK for ultrasound transmitter. Version 0.3, 2007-09-05 11 VLSI VS2000 PRELIMINARY y Solution VS2000 5. VS2000 FUNCTIONAL BLOCKS USB The USB peripheral handles USB 1.1 Full Speed harware protocol. Low speed communication is not supported, but is correctly ignored. The USBP pin has a software-controllable 1.5kΩ pull-up. A control endpoint (1 IN and 1 OUT) and upto 6 other endpoints (3 IN and 3 OUT) can be used simultaneously. Bulk, interrupt, and isochronous transfer modes are selectable for each endpoint. USB receive from USB host to device (OUT) uses a 2 KiB buffer, thus allowing very high transfer speeds. USB transmit from device to USB host (IN) also uses a 2 KiB buffer and allows all IN endpoints to be ready to transmit simultaneously. Double-buffering is also possible, but not usually required. The firmware uses the USB peripheral to implement a 6-channel USB Audio Device and USB Human Interface Device. 5.3 Analog Section The third regulator provides power for the analog section. The analog section consists of digital to analog converters and earphone driver. This includes a buffered common voltage generator (CBUF, around 1.2 V) that can be used as a virtual ground for headphones. The AVDD regulator output pin must be connected to AVDD1..AVDD3 pins with proper bypass capacitors, because they are not connected internally. The USB pins use the internal AVDD voltage, and the firmware configures AVDD to 3.6 V when USB is attached. Low AVDD voltage can be monitored by software. Currently the firmware does not take advantage of this feature. CBUF contains a short-circuit protection. It disconnects the CBUF driver if pin is shorted to ground. In practise this only happens with external power regulation, because there is a limit to how much power the internal regulators can provide. Version 0.3, 2007-09-05 12 VLSI VS2000 PRELIMINARY y Solution 6 VS2000 6. FIRMWARE OPERATION Firmware Operation The firmware uses the following pins (see the example schematics in Section 7): Pin VHIGH PWRBTN USBN USBP GPIO0 0 GPIO0 1 GPIO0 2 GPIO0 3 GPIO0 4 GPIO0 5 GPIO0 6 GPIO0 7 GPIO0 8 GPIO0 9 GPIO0 10 GPIO0 11 GPIO0 12 GPIO0 13 GPIO0 14 GPIO1 0 / XCS GPIO1 1 / SCLK GPIO1 2 / SI GPIO1 3 / SO GPIO1 4 / TX GPIO1 5 / RX Description VBUS with diode to VHIGH Power button starts regulator + VBUS-triggered (Mode Select) external 1 MΩ pull-up external 1 MΩ pull-up external 1 MΩ pull-down resistor, Key 1 connects a 100 kΩ pull-up resistor (Vol-) external 1 MΩ pull-down resistor, Key 2 connects a 100 kΩ pull-up resistor (Vol+) external 1 MΩ pull-down resistor, Key 3 connects a 100 kΩ pull-up resistor (Pause) external 1 MΩ pull-down resistor, Key 4 connects a 100 kΩ pull-up resistor (Play) external 1 MΩ pull-down resistor, Key 5 connects a 100 kΩ pull-up resistor (Rewind) external 1 MΩ pull-down resistor, Key 6 connects a 100 kΩ pull-up resistor (Fast Forward) external 1 MΩ pull-down resistor, Key 7 connects a 100 kΩ pull-up resistor (Effect Level Select) external 100 kΩ pull-up resistor USB LED - Red Effect Level LED - Green (PWM-controlled) Tracking LED - Red Tracking LED - Green Headtracker input right Headtracker input left Audio LED, External power control, with 1 MΩ pull-down resistor external pull-up to enable SPI EEPROM boot 820 Hz headtracker transmit / SPI EEPROM SCLK SPI EEPROM MISO 40 kHz headtracker transmit / SPI EEPROM MOSI UART transmit UART receive Tracking LEDs indicate the operation mode: Green On Green Off, Red Off Green Off, Red On Tracking On, RED On if tracking error is detected Tracking Off, spatial processing active Bypass mode, no spatial processing, down-mixing only USB LED is lit when setup packets are received, i.e. during device configuration, and when audio controls are changed. Audio LED is lit when audio data is transferred and is turned off after a short timeout when audio transmission stops. Version 0.3, 2007-09-05 13 VLSI VS2000 PRELIMINARY y Solution 6.1 VS2000 6. FIRMWARE OPERATION SPI Boot The first boot method is SPI EEPROM. If GPIO1[0] is low after reset, SPI boot is skipped. If GPIO1[0] is high, it is assumed to have a pull-up resistor and SPI boot is tried. First the first four bytes of the SPI EEPROM are read using 16-bit address. If the bytes are “VLSI”, a 16-bit EEPROM is assumed and the boot continues. If the last 3 bytes are read as “VLS”, a 24-bit EEPROM is assumed and boot continues in 24-bit mode. Both 16-bit and 24-bit EEPROM should have the “VLSI” string starting at address 0, and the rest of the boot data starting at address 4. If the identification is not found, SPI EEPROM boot is skipped. Boot records are read from EEPROM until an execute record is reached. Unknown records are skipped using the data length field. Byte 0 1,2 3, 4 5.. 6.2 Description type 0=I-mem 1=X-mem 2=Y-mem 3=execute data len lo, hi – data length in bytes address lo, hi – record address data* UART Boot/Monitor When byte 0xef is sent to RX at 115200 bps, the firmware enters monitor mode and communicates with vs3emu. Memory contents can be displayed, executables can be loaded and run, or the firmware code can be restarted or continued. The UART is also a convenient way to program or reprogram the SPI EEPROM. Version 0.3, 2007-09-05 14 VLSI VS2000 PRELIMINARY y Solution 6.3 VS2000 6. FIRMWARE OPERATION Default Firmware Features When USB cable insertion is detected by the firmware, USB handling code is started. The internal clock is configured to 4.0× 12 MHz = 48 MHz, the analog power is configured to 3.6 V, the core power to 2.5 V, the USB peripheral is initialized, and the USB pull-up resistor is enabled. In addition to the power button, upto 7 keys are connected to GPIO0[6..0] so that they connect a 100 kΩ pull-up to the I/O when the button is pressed, and 1 MΩ pull-downs keep the lines low otherwise. Some of the keys are used for different direct modes, the rest are available to PC through USB Human Interface Device. 6.3.1 USB Audio Device VS2000 appears as an USB Composite Device with USB Audio Device and USB Human Interface Device. The USB Audio Device has 6 16-bit channels, and a feature unit that includes master volume, master mute, master bass, and master treble controls. These controls can be changed using system tools (in Windows using the volume control panel and advanced audio settings). Headtracker transmit is only enabled when audio transmission is active. 6.3.2 USB Human Interface Device The USB Human Interface Device (HID) transmits information about the state of the device buttons to the host machine. With proper software HID can also be used for reading and writing VS2000 memory, for example monitoring the headtracker state, and changing some advanced features. Volume Decrement, Volume Increment Volume can be turned up or down with 0.5 dB steps using the volume buttons. A short press changes the volume by 0.5 dB, a long press will change the volume by approximately 8 dB every second. Using the volume buttons is always possible, regardless of whether the host machine supports USB Human Interface Devices or not. If the host machine supports USB Human Interface Devices, it can detect the press of volume buttons and set the volume using the USB Audio Device controls. Pause, Play, Rewind, Fast Forward These buttons are Human Interface Device buttons only. Their operation depends on the host machine, and the application that is active at the time. Power Button A press of the power button turns on the system. Insertion of the device to the USB port can also turn the unit on. A long press (2 seconds) of the power button will turn off the device. Short press of the power button switches the processing mode between Tracking On, Tracking Off, and Bypass. Version 0.3, 2007-09-05 15 VLSI VS2000 PRELIMINARY y Solution VS2000 6. FIRMWARE OPERATION In both tracking modes the full 3D processing is active. In the bypass-mode the 3D processing is replaced by a simple 6-channel to 2-channel matrixing operation. The power button is not a Human Interface Device button. Effect Level Button The effect level button selects between four predefined levels of room response. The default levels are off, low, medium, and high. The default setting is the medium level. The effect level button is not a Human Interface Device button. Version 0.3, 2007-09-05 16 VLSI VS2000 PRELIMINARY y Solution 7 VS2000 7. EXAMPLE APPLICATION Example Application Figure 3: VS2000 Example Application The example application consists of five parts. 1. VS2000 Unit - contains the VS2000 chip and other active electronics, buttons and LEDs. 2. Transmitter - ultrasound transmitter element, is powered and controlled by VS2000 Unit. 3. Sensors - ultrasound receivers, are read by VS2000 Unit. 4. USB - the audio source. USB also powers the system. 5. Headphones - for audio output. Figure 4: VS2000 Unit Version 0.3, 2007-09-05 17 VLSI Solution VS2000 PRELIMINARY y VS2000 7. EXAMPLE APPLICATION Figure 5: VS2000 Example Schematic Version 0.3, 2007-09-05 18 VLSI VS2000 PRELIMINARY y Solution 7.1 VS2000 7. EXAMPLE APPLICATION Usage Hints Linux Mplayer requires the following options to play the 6-channel audio instead of 2-channel: -channels 6 -af channels=6:6:0:0:1:1:2:4:3:5:4:2:5:3. The first option selects six channels, and the second option corrects the channel mapping. Mplayer does not determine the output channel mapping automatically. Also an option like -ao alsa:device=hw=1.0 may be needed to select the USB Audio Device in case the system has multiple audio devices. MAC The MAC system player seems to only play the two-channel mix of a DVD, and can not be configured for multichannel sound, as far as we could determine. Mplayer requires the following options to play the 6-channel audio instead of 2-channel: -channels 6 -af channels=6:6:0:0:1:1:2:4:3:5:4:2:5:3. The first option selects six channels, and the second option corrects the channel mapping. Mplayer does not determine the output channel mapping automatically. Windows 2000Pro, XP, Vista Windows MediaPlayer should play all the channels and it also processes the channel order information, thus plays the channels in the right order. Some old third-party DVD player applications only play 2-channel audio. Version 0.3, 2007-09-05 19 VLSI VS2000 PRELIMINARY y Solution 8 VS2000 8. DOCUMENT VERSION CHANGES Document Version Changes This chapter describes the most important changes to this document. 8.1 Version 0.3, 2007-09-05 • Example application picture and board photo added. • First public release. 8.2 Version 0.2, 2007-08-31 • Headtracker left and right swapped. • Example schematic and pictures updated. • Usage hints chapter added. 8.3 Version 0.1, 2007-06-15 • First pre-release version. Version 0.3, 2007-09-05 20 VLSI Solution VS2000 PRELIMINARY y VS2000 9. CONTACT INFORMATION 9 Contact Information VLSI Solution Oy Entrance G, 2nd floor Hermiankatu 8 FIN-33720 Tampere FINLAND Fax: +358-3-3140-8288 Phone: +358-3-3140-8200 Email: [email protected] URL: http://www.vlsi.fi/ Version 0.3, 2007-09-05 21