1=========================================== 2Sound Blaster Live mixer / default DSP code 3=========================================== 4 5 6The EMU10K1 chips have a DSP part which can be programmed to support 7various ways of sample processing, which is described here. 8(This article does not deal with the overall functionality of the 9EMU10K1 chips. See the manuals section for further details.) 10 11The ALSA driver programs this portion of chip by default code 12(can be altered later) which offers the following functionality: 13 14 15IEC958 (S/PDIF) raw PCM 16======================= 17 18This PCM device (it's the 4th PCM device (index 3!) and first subdevice 19(index 0) for a given card) allows to forward 48kHz, stereo, 16-bit 20little endian streams without any modifications to the digital output 21(coaxial or optical). The universal interface allows the creation of up 22to 8 raw PCM devices operating at 48kHz, 16-bit little endian. It would 23be easy to add support for multichannel devices to the current code, 24but the conversion routines exist only for stereo (2-channel streams) 25at the time. 26 27Look to tram_poke routines in lowlevel/emu10k1/emufx.c for more details. 28 29 30Digital mixer controls 31====================== 32 33These controls are built using the DSP instructions. They offer extended 34functionality. Only the default build-in code in the ALSA driver is described 35here. Note that the controls work as attenuators: the maximum value is the 36neutral position leaving the signal unchanged. Note that if the same destination 37is mentioned in multiple controls, the signal is accumulated and can be wrapped 38(set to maximal or minimal value without checking of overflow). 39 40 41Explanation of used abbreviations: 42 43DAC 44 digital to analog converter 45ADC 46 analog to digital converter 47I2S 48 one-way three wire serial bus for digital sound by Philips Semiconductors 49 (this standard is used for connecting standalone DAC and ADC converters) 50LFE 51 low frequency effects (subwoofer signal) 52AC97 53 a chip containing an analog mixer, DAC and ADC converters 54IEC958 55 S/PDIF 56FX-bus 57 the EMU10K1 chip has an effect bus containing 16 accumulators. 58 Each of the synthesizer voices can feed its output to these accumulators 59 and the DSP microcontroller can operate with the resulting sum. 60 61 62``name='Wave Playback Volume',index=0`` 63--------------------------------------- 64This control is used to attenuate samples for left and right PCM FX-bus 65accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 66The result samples are forwarded to the front DAC PCM slots of the AC97 codec. 67 68``name='Wave Surround Playback Volume',index=0`` 69------------------------------------------------ 70This control is used to attenuate samples for left and right PCM FX-bus 71accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 72The result samples are forwarded to the rear I2S DACs. These DACs operates 73separately (they are not inside the AC97 codec). 74 75``name='Wave Center Playback Volume',index=0`` 76---------------------------------------------- 77This control is used to attenuate samples for left and right PCM FX-bus 78accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 79The result is mixed to mono signal (single channel) and forwarded to 80the ??rear?? right DAC PCM slot of the AC97 codec. 81 82``name='Wave LFE Playback Volume',index=0`` 83------------------------------------------- 84This control is used to attenuate samples for left and right PCM FX-bus 85accumulators. ALSA uses accumulators 0 and 1 for left and right PCM. 86The result is mixed to mono signal (single channel) and forwarded to 87the ??rear?? left DAC PCM slot of the AC97 codec. 88 89``name='Wave Capture Volume',index=0``, ``name='Wave Capture Switch',index=0`` 90------------------------------------------------------------------------------ 91These controls are used to attenuate samples for left and right PCM FX-bus 92accumulator. ALSA uses accumulators 0 and 1 for left and right PCM. 93The result is forwarded to the ADC capture FIFO (thus to the standard capture 94PCM device). 95 96``name='Synth Playback Volume',index=0`` 97---------------------------------------- 98This control is used to attenuate samples for left and right MIDI FX-bus 99accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples. 100The result samples are forwarded to the front DAC PCM slots of the AC97 codec. 101 102``name='Synth Capture Volume',index=0``, ``name='Synth Capture Switch',index=0`` 103-------------------------------------------------------------------------------- 104These controls are used to attenuate samples for left and right MIDI FX-bus 105accumulator. ALSA uses accumulators 4 and 5 for left and right PCM. 106The result is forwarded to the ADC capture FIFO (thus to the standard capture 107PCM device). 108 109``name='Surround Playback Volume',index=0`` 110------------------------------------------- 111This control is used to attenuate samples for left and right rear PCM FX-bus 112accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples. 113The result samples are forwarded to the rear I2S DACs. These DACs operate 114separately (they are not inside the AC97 codec). 115 116``name='Surround Capture Volume',index=0``, ``name='Surround Capture Switch',index=0`` 117-------------------------------------------------------------------------------------- 118These controls are used to attenuate samples for left and right rear PCM FX-bus 119accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples. 120The result is forwarded to the ADC capture FIFO (thus to the standard capture 121PCM device). 122 123``name='Center Playback Volume',index=0`` 124----------------------------------------- 125This control is used to attenuate sample for center PCM FX-bus accumulator. 126ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded 127to the ??rear?? right DAC PCM slot of the AC97 codec. 128 129``name='LFE Playback Volume',index=0`` 130-------------------------------------- 131This control is used to attenuate sample for center PCM FX-bus accumulator. 132ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded 133to the ??rear?? left DAC PCM slot of the AC97 codec. 134 135``name='AC97 Playback Volume',index=0`` 136--------------------------------------- 137This control is used to attenuate samples for left and right front ADC PCM slots 138of the AC97 codec. The result samples are forwarded to the front DAC PCM 139slots of the AC97 codec. 140 141.. note:: 142 This control should be zero for the standard operations, otherwise 143 a digital loopback is activated. 144 145 146``name='AC97 Capture Volume',index=0`` 147-------------------------------------- 148This control is used to attenuate samples for left and right front ADC PCM slots 149of the AC97 codec. The result is forwarded to the ADC capture FIFO (thus to 150the standard capture PCM device). 151 152.. note:: 153 This control should be 100 (maximal value), otherwise no analog 154 inputs of the AC97 codec can be captured (recorded). 155 156``name='IEC958 TTL Playback Volume',index=0`` 157--------------------------------------------- 158This control is used to attenuate samples from left and right IEC958 TTL 159digital inputs (usually used by a CDROM drive). The result samples are 160forwarded to the front DAC PCM slots of the AC97 codec. 161 162``name='IEC958 TTL Capture Volume',index=0`` 163-------------------------------------------- 164This control is used to attenuate samples from left and right IEC958 TTL 165digital inputs (usually used by a CDROM drive). The result samples are 166forwarded to the ADC capture FIFO (thus to the standard capture PCM device). 167 168``name='Zoom Video Playback Volume',index=0`` 169--------------------------------------------- 170This control is used to attenuate samples from left and right zoom video 171digital inputs (usually used by a CDROM drive). The result samples are 172forwarded to the front DAC PCM slots of the AC97 codec. 173 174``name='Zoom Video Capture Volume',index=0`` 175-------------------------------------------- 176This control is used to attenuate samples from left and right zoom video 177digital inputs (usually used by a CDROM drive). The result samples are 178forwarded to the ADC capture FIFO (thus to the standard capture PCM device). 179 180``name='IEC958 LiveDrive Playback Volume',index=0`` 181--------------------------------------------------- 182This control is used to attenuate samples from left and right IEC958 optical 183digital input. The result samples are forwarded to the front DAC PCM slots 184of the AC97 codec. 185 186``name='IEC958 LiveDrive Capture Volume',index=0`` 187-------------------------------------------------- 188This control is used to attenuate samples from left and right IEC958 optical 189digital inputs. The result samples are forwarded to the ADC capture FIFO 190(thus to the standard capture PCM device). 191 192``name='IEC958 Coaxial Playback Volume',index=0`` 193------------------------------------------------- 194This control is used to attenuate samples from left and right IEC958 coaxial 195digital inputs. The result samples are forwarded to the front DAC PCM slots 196of the AC97 codec. 197 198``name='IEC958 Coaxial Capture Volume',index=0`` 199------------------------------------------------ 200This control is used to attenuate samples from left and right IEC958 coaxial 201digital inputs. The result samples are forwarded to the ADC capture FIFO 202(thus to the standard capture PCM device). 203 204``name='Line LiveDrive Playback Volume',index=0``, ``name='Line LiveDrive Playback Volume',index=1`` 205---------------------------------------------------------------------------------------------------- 206This control is used to attenuate samples from left and right I2S ADC 207inputs (on the LiveDrive). The result samples are forwarded to the front 208DAC PCM slots of the AC97 codec. 209 210``name='Line LiveDrive Capture Volume',index=1``, ``name='Line LiveDrive Capture Volume',index=1`` 211-------------------------------------------------------------------------------------------------- 212This control is used to attenuate samples from left and right I2S ADC 213inputs (on the LiveDrive). The result samples are forwarded to the ADC 214capture FIFO (thus to the standard capture PCM device). 215 216``name='Tone Control - Switch',index=0`` 217---------------------------------------- 218This control turns the tone control on or off. The samples for front, rear 219and center / LFE outputs are affected. 220 221``name='Tone Control - Bass',index=0`` 222-------------------------------------- 223This control sets the bass intensity. There is no neutral value!! 224When the tone control code is activated, the samples are always modified. 225The closest value to pure signal is 20. 226 227``name='Tone Control - Treble',index=0`` 228---------------------------------------- 229This control sets the treble intensity. There is no neutral value!! 230When the tone control code is activated, the samples are always modified. 231The closest value to pure signal is 20. 232 233``name='IEC958 Optical Raw Playback Switch',index=0`` 234----------------------------------------------------- 235If this switch is on, then the samples for the IEC958 (S/PDIF) digital 236output are taken only from the raw FX8010 PCM, otherwise standard front 237PCM samples are taken. 238 239``name='Headphone Playback Volume',index=1`` 240-------------------------------------------- 241This control attenuates the samples for the headphone output. 242 243``name='Headphone Center Playback Switch',index=1`` 244--------------------------------------------------- 245If this switch is on, then the sample for the center PCM is put to the 246left headphone output (useful for SB Live cards without separate center/LFE 247output). 248 249``name='Headphone LFE Playback Switch',index=1`` 250------------------------------------------------ 251If this switch is on, then the sample for the center PCM is put to the 252right headphone output (useful for SB Live cards without separate center/LFE 253output). 254 255 256PCM stream related controls 257=========================== 258 259``name='EMU10K1 PCM Volume',index 0-31`` 260---------------------------------------- 261Channel volume attenuation in range 0-0xffff. The maximum value (no 262attenuation) is default. The channel mapping for three values is 263as follows: 264 265* 0 - mono, default 0xffff (no attenuation) 266* 1 - left, default 0xffff (no attenuation) 267* 2 - right, default 0xffff (no attenuation) 268 269``name='EMU10K1 PCM Send Routing',index 0-31`` 270---------------------------------------------- 271This control specifies the destination - FX-bus accumulators. There are 272twelve values with this mapping: 273 274* 0 - mono, A destination (FX-bus 0-15), default 0 275* 1 - mono, B destination (FX-bus 0-15), default 1 276* 2 - mono, C destination (FX-bus 0-15), default 2 277* 3 - mono, D destination (FX-bus 0-15), default 3 278* 4 - left, A destination (FX-bus 0-15), default 0 279* 5 - left, B destination (FX-bus 0-15), default 1 280* 6 - left, C destination (FX-bus 0-15), default 2 281* 7 - left, D destination (FX-bus 0-15), default 3 282* 8 - right, A destination (FX-bus 0-15), default 0 283* 9 - right, B destination (FX-bus 0-15), default 1 284* 10 - right, C destination (FX-bus 0-15), default 2 285* 11 - right, D destination (FX-bus 0-15), default 3 286 287Don't forget that it's illegal to assign a channel to the same FX-bus accumulator 288more than once (it means 0=0 && 1=0 is an invalid combination). 289 290``name='EMU10K1 PCM Send Volume',index 0-31`` 291--------------------------------------------- 292It specifies the attenuation (amount) for given destination in range 0-255. 293The channel mapping is following: 294 295* 0 - mono, A destination attn, default 255 (no attenuation) 296* 1 - mono, B destination attn, default 255 (no attenuation) 297* 2 - mono, C destination attn, default 0 (mute) 298* 3 - mono, D destination attn, default 0 (mute) 299* 4 - left, A destination attn, default 255 (no attenuation) 300* 5 - left, B destination attn, default 0 (mute) 301* 6 - left, C destination attn, default 0 (mute) 302* 7 - left, D destination attn, default 0 (mute) 303* 8 - right, A destination attn, default 0 (mute) 304* 9 - right, B destination attn, default 255 (no attenuation) 305* 10 - right, C destination attn, default 0 (mute) 306* 11 - right, D destination attn, default 0 (mute) 307 308 309 310MANUALS/PATENTS 311=============== 312 313ftp://opensource.creative.com/pub/doc 314------------------------------------- 315 316LM4545.pdf 317 AC97 Codec 318m2049.pdf 319 The EMU10K1 Digital Audio Processor 320hog63.ps 321 FX8010 - A DSP Chip Architecture for Audio Effects 322 323 324WIPO Patents 325------------ 326 327WO 9901813 (A1) 328 Audio Effects Processor with multiple asynchronous streams 329 (Jan. 14, 1999) 330 331WO 9901814 (A1) 332 Processor with Instruction Set for Audio Effects (Jan. 14, 1999) 333 334WO 9901953 (A1) 335 Audio Effects Processor having Decoupled Instruction 336 Execution and Audio Data Sequencing (Jan. 14, 1999) 337 338 339US Patents (https://www.uspto.gov/) 340----------------------------------- 341 342US 5925841 343 Digital Sampling Instrument employing cache memory (Jul. 20, 1999) 344 345US 5928342 346 Audio Effects Processor integrated on a single chip 347 with a multiport memory onto which multiple asynchronous 348 digital sound samples can be concurrently loaded 349 (Jul. 27, 1999) 350 351US 5930158 352 Processor with Instruction Set for Audio Effects (Jul. 27, 1999) 353 354US 6032235 355 Memory initialization circuit (Tram) (Feb. 29, 2000) 356 357US 6138207 358 Interpolation looping of audio samples in cache connected to 359 system bus with prioritization and modification of bus transfers 360 in accordance with loop ends and minimum block sizes 361 (Oct. 24, 2000) 362 363US 6151670 364 Method for conserving memory storage using a 365 pool of short term memory registers 366 (Nov. 21, 2000) 367 368US 6195715 369 Interrupt control for multiple programs communicating with 370 a common interrupt by associating programs to GP registers, 371 defining interrupt register, polling GP registers, and invoking 372 callback routine associated with defined interrupt register 373 (Feb. 27, 2001) 374