VS1000

VS1000b VS1000 VS1000 - Ogg Vorbis Player IC with USB and NAND FLASH Interface 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 • Power button pin, software-controlled power-off • USB Full Speed hardware • NAND FLASH interface with ECC • 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) Description VS1000 is a single-chip Ogg Vorbis (license-free audio codec) player. VS1000 contains a high-performance low-power DSP core VS DSP4 , NAND FLASH interface, Full Speed USB port, general purpose I/O pins, SPI, UART, as well as a highquality variable-sample-rate stereo DAC, and an earphone amplifier and a common voltage buffer. VS1000 firmware implements a default player that reads and plays files from the NAND FLASH. The player can be customized or replaced by using boot from NAND FLASH. When connected to USB, the firmware implements USB Mass Storage Device protocol or acts as an Audio Device, providing a single-chip USB headphone application. EarSpeaker spatial processing provides more natural sound in headphone listening conditions. It widens the stereo image and positions the sound sources outside the listener’s head. SPI EEPROM can be used to load code in applications that do not use NAND FLASH. Firmware Features • Implements USB Mass Storage Device and Audio Device • NAND FLASH handling with error correction, block remapping, and wear levelling • Default player application in firmware – Decodes Ogg Vorbis, sound level normalization using Replay Gain – Pause / Play – Volume control – Next / Previous Song – Rewind and Fast Forward – Random Play – EarSpeaker Spatial Processing • Bass and treble controls for customized player • NAND FLASH boot for customized player • SPI FLASH boot for special applications • UART for debugging and special applications Version 1.0, 2007-09-11 1 VLSI Solution y VS1000b VS1000 CONTENTS Contents 1 Disclaimer 4 2 Definitions 4 3 Characteristics & Specifications 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analog Characteristics of Audio Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . Analog Characteristics of Regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analog Characteristics of VHIGH voltage monitor . . . . . . . . . . . . . . . . . . . . Analog Characteristics of CVDD voltage monitor . . . . . . . . . . . . . . . . . . . . . Analog Characteristics of USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Digital Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4 5 5 6 6 6 7 7 7 4 Packages and Pin Descriptions 4.1 4.2 Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LQFP-48 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8 9 5 Example Schematic 11 6 VS1000 Functional Blocks 6.1 6.2 6.3 Regulator Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Digital Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analog Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 12 13 14 Version 1.0, 2007-09-11 2 VLSI Solution y VS1000b VS1000 LIST OF FIGURES 7 Firmware Operation 7.1 7.2 7.3 7.4 SPI Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NAND FLASH Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UART Boot/Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Default Firmware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4.1 7.4.2 7.5 USB Mass Storage and Audio Device . . . . . . . . . . . . . . . . . . . . . . . Default Player Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 15 16 16 17 17 17 19 19 20 Supported Audio Codecs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5.1 Supported Ogg Vorbis Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6 EarSpeaker Spatial Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 VS1000 Errata 21 9 Document Version Changes 22 10 Contact Information 23 List of Figures 1 2 3 Pin Configuration, LQFP-48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VS1000 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EarSpeaker externalized sound sources vs. normal inside-the-head sound . . . . . . . . . 8 12 20 Version 1.0, 2007-09-11 3 VLSI Solution y VS1000b VS1000 1. DISCLAIMER 1 Disclaimer 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 Analog Positive Supply Digital Positive Supply I/O Positive Supply Voltage at Any Digital Input Total Injected Current on Pins Operating Temperature Storage Temperature 1 2 Symbol VHIGH AVDD CVDD IOVDD Min -0.3 -0.3 -0.3 -0.3 -0.3 -40 -65 Max 5.25 3.6 2.7 3.6 IOVDD+0.31 ±200 2 +85 +150 Unit V V V V V mA ◦C ◦C Must not exceed 3.6 V Latch-up limit Version 1.0, 2007-09-11 4 VLSI Solution y VS1000b3. CHARACTERISTICS & SPECIFICATIONS VS1000 3.2 Recommended Operating Conditions Symbol AGND DGND VHIGH AVDD CVDD IOVDD XTALI CLKU CLKI Min -40 AVDD+0.3 2.75 2.2 1.8 12 48 12 40 Typ 0.0 4.0 2.8 2.3 2.8 125 Max +85 5.25 3.6 2.65 3.6 13 48 48 60 Unit ◦C V V V V V MHz MHz MHz % Parameter Operating temperature Analog and digital ground 1 Regulator input voltage2 Analog positive supply3 Digital positive supply 3 I/O positive supply3 Input clock frequency4 Internal clock frequency, USB connected Internal clock frequency, USB disconnected Master clock duty cycle 1 2 50 Must be connected together as close the device as possible for latch-up immunity. 4.0 V is required for compliant USB level. 3 Regulator output of the device. 4 The maximum sample rate that can be played with correct speed is XTALI/256. With 12 MHz XTALI sample rates over 46875 Hz are played at 46875 Hz. 5 To be able to use USB, XTALI must be 12 MHz. 3.3 Analog Characteristics of Audio Outputs Unless otherwise noted: AVDD=2.8V, CVDD=2.4V, IOVDD=2.8V, TA=-40..+85◦ C, XTALI=12 MHz, Internal Clock Multiplier 3.0×. DAC tested with full-scale output sinewave, measurement bandwidth 20..20000 Hz, analog output load: LEFT to CBUF 30 Ω, RIGHT to CBUF 30 Ω. Parameter DAC Resolution Dynamic range (DAC unmuted, A-weighted, min gain) S/N ratio (full scale signal, no load) S/N ratio (full scale signal, 30 ohm load) Total harmonic distortion, max level, no load Total harmonic distortion, max level, 30 ohm load Crosstalk (L/R to R/L), 30 ohm load, without CBUF 1 Crosstalk (L/R to R/L), 30 ohm load, with CBUF Gain mismatch (L/R to R/L) Frequency response Full scale output voltage Deviation from linear phase Analog output load resistance Analog output load capacitance DC level (CBUF, LEFT, RIGHT) CBUF disconnect current (short-circuit protection) 1 2 Symbol IDR SNR SNRL THD THDL XTALK1 XTALK2 GERR AERR LEVEL PH AOLR AOLC Min 75 Typ 18 96 92 90 0.01 0.1 75 54 Max 0.3 -0.5 -0.05 450 530 0 302 0.5 0.05 600 5 1003 1.3 200 Unit bits dB dB dB % % dB dB dB dB mVrms ◦ 1.1 130 Ω pF V mA Loaded from Left/Right pin to analog ground via 100 µF capacitors. AOLR may be lower than Typical, but distortion performance may be compromised. Also, there is a maximum current that the internal regulators can provide. 3 CBUF must have external 10 Ω + 47 nF load, LEFT and RIGHT must have external 20 Ω + 10 nF load for optimum stability and ESD tolerance. Version 1.0, 2007-09-11 5 VLSI Solution y VS1000b3. CHARACTERISTICS & SPECIFICATIONS VS1000 3.4 Analog Characteristics of Regulators Symbol Min 1.7 50 Typ Max 3.6 70 Unit V mV V V mV/mA mV/V mA V mV V V mA mV/mA mV/V V mV V V mA mV/mA mV/V Parameter IOVDD Recommended voltage setting range Voltage setting step size Default setting, reset mode 1 Default setting, active mode 2 Load regulation Line regulation from VHIGH Continuous current CVDD Recommended voltage setting range Voltage setting step size Default setting, reset mode 1 Default setting, active mode 2 Continuous current Load regulation Line regulation from VHIGH AVDD Recommended voltage setting range Voltage setting step size Default setting, reset mode 1 Default setting, active mode 2 Continuous current Load regulation Line regulation from VHIGH 1 2 60 1.8 1.8/3.63 4.0 2.0 304 40 2.6 55 1.8 35 48 1.8 2.2 304 2.0 2.0 35 2.6 35 46 2.5 2.7 304 1.5 2.0 3.6 55 70 Device enters reset mode when XRESET pin is pulled low. Device enters active mode when XRESET pin is pulled high after reset mode. Regulator settings can be modified when booted from external memory (see section 7). 3 Depends on GPIO0 7 pin status in boot (see section 7). 4 Device is tested with a 30 mA load. 3.5 Analog Characteristics of VHIGH voltage monitor Parameter Trigger voltage Hysteresis Symbol AMON Min Typ 1.07×AVDD 50 Max Unit V mV 3.6 Analog Characteristics of CVDD voltage monitor Symbol CMON Min 1.40 Typ 1.53 2 Max Unit V mV Parameter Trigger voltage Hysteresis Version 1.0, 2007-09-11 6 VLSI Solution y VS1000b3. CHARACTERISTICS & SPECIFICATIONS VS1000 3.7 Analog Characteristics of USB Symbol Min 0.065 0.171×AVDD 0.300×AVDD AVDD-0.165 0.650×AVDD 0 2.7 0.7×AVDD -0.2 0.8 200 -2.0 Typ Max 0.102 0.270×AVDD AVDD AVDD-0.065 0.829×AVDD 0.700×AVDD 0.943×AVDD AVDD+0.3 0.3×AVDD 2.5 2.0 Unit V V V V V V V V V V mV µA Parameter Drive low level, 2.32 mA load Drive low level, 6.1×AVDD mA load Drive low level, 10.71×AVDD mA load Drive high level, -2.32 mA load Drive high level, -6.1×AVDD mA load Drive high level, -10.71×AVDD mA load USBP level, with 15 kΩ pull-down High-Level input voltage (single-ended) Low-Level input voltage (single-ended) Differential input common voltage, AVDD≥3.3V Differential input signal level, AVDD≥3.3V Input leakage current 3.8 Power Consumption Max 55 25 48 Unit mA mA mA µA µA mW mW mW Parameter Symbol Min Typ Current Consumption of AVDD, no signal 3.4 Current Consumption of AVDD, sine test, CBUF + 30Ω load 33 Current Consumption of CVDD, sine test 3.0× clock 13 Current Consumption of USB suspend mode 1 650 Current Consumption, Reset @ 25 ◦ C 24 Example application (see Section 5) IOVDD=3.3V AVDD=2.8V CVDD=2.5V Total Power, play mode, CBUF + 30Ω load 120 Example application (see Section 5) IOVDD=2.7V AVDD=2.6V CVDD=2.2V Total Power, pause mode 10 Total Power, play mode, CBUF + 30Ω load 80 1 Requires user code support 3.9 Digital Characteristics Symbol Min 0.7×IOVDD -0.2 0.7×IOVDD 0.7×IOVDD -1.0 0.3×IOVDD 1.0 50 Typ Max IOVDD+0.3 0.3×IOVDD 0.3×IOVDD Unit V V V V V V µA ns Parameter High-Level Input Voltage Low-Level Input Voltage High-Level Output Voltage, -1.0 mA load 1 Low-Level Output Voltage, 1.0 mA load 1 XTALO high-level output voltage, -0.1 mA load XTALO low-level output voltage, 0.1 mA load Input leakage current Rise time of all output pins, load = 30 pF 1 1 Pins GPIO0 [14:0], GPIO1 [5:0]. Version 1.0, 2007-09-11 7 VLSI Solution y VS1000b VS1000 4. PACKAGES AND PIN DESCRIPTIONS 4 4.1 Packages and Pin Descriptions Packages LPQFP-48 is lead (Pb) free and 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 1.0, 2007-09-11 8 VLSI Solution y VS1000b VS1000 4. PACKAGES AND PIN DESCRIPTIONS 4.2 LQFP-48 Pin Descriptions 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 Nand-flash IO0 / General-purpose IO Port 0, bit 0 Nand-flash IO1 / General-purpose IO Port 0, bit 1 Nand-flash IO2 / General-purpose IO Port 0, bit 2 Nand-flash IO3 / General-purpose IO Port 0, bit 3 Core & I/O ground I/O power supply Test mode input (active high), connect to DGND Nand-flash IO4 / General-purpose IO Port 0, bit 4 Nand-flash IO5 / General-purpose IO Port 0, bit 5 Nand-flash IO6 / General-purpose IO Port 0, bit 6 Nand-flash IO7 / General-purpose IO Port 0, bit 7 Nand-flash READY / General-purpose IO Port 0, bit 8 Nand-flash RD / General-purpose IO Port 0, bit 9 Nand-flash CE / General-purpose IO Port 0, bit 10 Nand-flash CLE / General-purpose IO Port 0, bit 12 Nand-flash ALE / General-purpose IO Port 0, bit 13 Core & I/O ground I/O power supply Nand-flash WR / 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 Pin Name XRESET NFDIO0 / GPIO0 0 NFDIO1 / GPIO0 1 NFDIO2 / GPIO0 2 NFDIO3 / GPIO0 3 DGND0 IOVDD1 TEST NFDIO4 / GPIO0 4 NFDIO5 / GPIO0 5 NFDIO6 / GPIO0 6 NFDIO7 / GPIO0 7 NFRDY / GPIO0 8 NFRD / GPIO0 9 NFCE / GPIO0 10 NFCLE / GPIO0 12 NFALE / GPIO0 13 DGND1 IOVDD2 NFWR / GPIO0 11 CS2 / 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 1.0, 2007-09-11 9 VLSI Solution y VS1000b VS1000 4. PACKAGES AND PIN DESCRIPTIONS Pin types: Type DI DO DIO AI AO Description Digital input, CMOS Input Pad Digital output, CMOS Input Pad Digital input/output Analog input Analog output 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 Version 1.0, 2007-09-11 10 VLSI Solution y VS1000b VS1000 5. EXAMPLE SCHEMATIC 5 Example Schematic Version 1.0, 2007-09-11 11 VLSI Solution y VS1000b VS1000 6. VS1000 FUNCTIONAL BLOCKS 6 VS1000 Functional Blocks LEFT RIGHT CBUF RCAP VHIGH PWRBTN Reference Stereo Earphone Driver Common Voltage Driver IOVDD AVDD1 AVDD2 AVDD3 Regulator Stereo DAC Voltage Monitor Regulator AVDD Regulator USBP USPN CVDD USB reset = 1 second Power off (pressed for 2 seconds) Volume Down Volume Up Rewind Fast Forward Random On / Off Version 1.0, 2007-09-11 17 VLSI Solution y VS1000b VS1000 7. FIRMWARE OPERATION Power Button A press of the power button turns on the system. After boot the power LED (the LED connected to SI) is turned on. After the startup a short press of the power button toggles between pause and play modes. In pause mode the power LED flashes. When the power button is pressed for 2 seconds, the system powers down. Volume Buttons 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. Previous / Next Buttons A song can be changed using the previous and next buttons. A short press of the previous button will restart the song if it has been played for at least 5 seconds, and go to the previous song otherwise. A short press of the next button goes to the next song. A long press of previous or next will rewind and fast forward the song, respectively. Feature Button The sixth button controls two features: the EarSpeaker spatial processing and the random play function. A long press of the feature button toggles the random play function. When random play becomes activated, a new song is automatically randomly selected. When random play mode is active, the feature LED (the LED connected to SO) will light up. A short press of the feature button will select between four EarSpeaker modes: off, minimal, normal, and extreme. Version 1.0, 2007-09-11 18 VLSI Solution y VS1000b VS1000 7. FIRMWARE OPERATION 7.5 7.5.1 Supported Audio Codecs Supported Ogg Vorbis Formats Min 1 64 Max 2 4096 48000 500 Unit samples Hz kbit/s Parameter Channels Window size Sample rate Bit rate Maximum window size for an Ogg Vorbis file is 8192, however only window sizes upto 4096 are in active use with sample rates not exceeding 48 kHz. With USB (12 MHz clock) sample rates above 46875 Hz are played back at 46875 Hz. There are no sample rate restrictions for lower sample rates: non-standard sample rates can be played back without a performance penalty. Only floor 1 is supported. No known current encoder uses floor 0. All one- and two-channel Ogg Vorbis files within the restrictions above should be playable with this decoder. Ogg Vorbis decoding supports Replay Gain technology. If the decoder finds a Replay Gain tag in the song header, the tag is parsed and the player software uses it to adjust the sound level. For a song without any Replay Gain tag, a default of -6 dB is used. For more details about Replay Gain, see http://en.wikipedia.org/wiki/Replay Gain and http://www.replaygain.org/. Version 1.0, 2007-09-11 19 VLSI Solution y VS1000b VS1000 7. FIRMWARE OPERATION 7.6 EarSpeaker Spatial Processing While listening to headphones the sound has a tendency to be localized inside the head. The sound field becomes flat and lacking a sensation of dimensions. This is an unnatural, awkward and sometimes even disturbing situation. This phenomenon is often referred in literature as ‘lateralization’, meaning ’in-the-head’ localization. Long-term listening to lateralized sound may lead to listening fatigue. All real-life sound sources are external, leaving traces of the acoustic wavefront that arrives to the ear drums. From these traces, the auditory system in the brain is able to judge the distance and angle of each sound source. In loudspeaker listening the sound is external and these traces are available. In headphone listening these traces are missing or ambiguous. The EarSpeaker processing makes listening via headphones more like listening to the same music from real loudspeakers or live. Once EarSpeaker processing is activated, the instruments are moved from inside to the outside of the head, making it easier to separate different instruments (see figure 3). The listening experience becomes more natural and pleasant, and the stereo image is sharper as the instruments are widely in front of the listener instead of being inside the head. Figure 3: EarSpeaker externalized sound sources vs. normal inside-the-head sound Note that EarSpeaker differs from any common spatial processing effects, such as echo, reverb, or bass boost. EarSpeaker accurately simulates the human auditory model and real listening environment acoustics. Thus it does not change the tonal character of the music by introducing artificial effects. EarSpeaker processing can be parameterized to a few different modes, each simulating a little different type of an acoustical situation and suiting different personal preferences as well as different types of recording. • Off: Best option when listening through loudspeakers or if the audio to be played contains binaural preprocessing • Minimal: Listening to normal musical scores with headphones, very subtle • Normal: Listening to normal musical scores with headphones, moves sound source further than minimal • Extreme: Old or ’dry’ recordings, or if the audio to be played is artificial Version 1.0, 2007-09-11 20 VLSI Solution y VS1000b VS1000 8. VS1000 ERRATA 8 VS1000 Errata This chapter describes the known problems with different VS1000 revisions. Most of the problems are correctable with user code that is loaded to IRAM. VS1000A Errata • • • • • • • • You can not have initialized Y data with NAND FLASH or Ramdisk boot. EarSpeaker initialization problem with other channel. Analog drivers are enabled too soon, causing a small click in headphones. Intermediate results are saturated in Vorbis windowing with full-scale sine sweep. If Flash does not contain a file system, user interface (including power off) can not be used. Ramdisk boot from VS1000 A.RUN only allows upto 512-byte programs directly. Volume is uninitialized with USB Audio Device if USB is already attached when power is turned on. In most cases Replay Gain fails if other tags are present. VS1000B Changes • • • • • • • • • • NAND FLASH and Ramdisk boot can have initialized Y data. EarSpeaker initialization fixed, EarSpeaker optimized from 12 MHz to 10 MHz (at 44.1 kHz). Small power-on click removed. User interface works even if there is no filesystem. (You can turn the power off.) NAND FLASH boot handles larger than 512-byte programs without a chain-loader routine (upto 8176 bytes). Ramdisk boot (VS1000 B.RUN) handles larger than 512-byte programs (upto 8192 bytes). When attached to USB, LED is flashed when there is read/write activity. LED is turned off when the file system has been flushed. Volume is always initialized, USB Audio Device can be powered on while attached to USB (powered from VBUS). USB Suspend + Resume are implemented (but need user tuning). Vorbis: Now uses adaptive accuracy for windowing, implements fast play mode, and has better synchronization after non-fatal errors. Replay gain has been fixed. Player: Fast play mode is used for better-sounding fast forward. Fast forward speeds up when the ff button is kept pressed. Player uses the suspend routine to implement low-power pause mode. Timeout turns the unit off after being 5 minutes in pause mode. The default maximum clock in player mode is 3.5×. Some new IRAM hooks: KeyEventHandler, MassStorage, USBSuspend, InitUSBDescriptors. • VS1000C Changes • Has the same firmware as version B. VS1000B/C Errata • NAND FLASH and Ramdisk boot needs one filler word after every Y data record. Version 1.0, 2007-09-11 21 VLSI Solution y VS1000b VS1000 9. DOCUMENT VERSION CHANGES 9 Document Version Changes This chapter describes the most important changes to this document. Version 1.0 for VS1000B/C, 2007-09-11 • Production version. • Maximum and operational limits updated. Version 0.4 for VS1000B/C, 2007-09-06 • Release for VS1000B / VS1000C. • Added VS1000 errata: Chapter 8. Version 0.3, 2007-05-09 • Updated example schematic in Chapter 5. Version 0.2, 2007-01-25 • Minor changes. Version 0.1, 2006-11-22 • First pre-release version. Version 1.0, 2007-09-11 22 VLSI Solution y VS1000b 10 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: sales@vlsi.fi URL: http://www.vlsi.fi/ VS1000 10. CONTACT INFORMATION Version 1.0, 2007-09-11 23