1 =========================================== 2 Sound Blaster Live mixer / default DSP code 3 =========================================== 4 5 6 The EMU10K1 chips have a DSP part which can be programmed to support 7 various ways of sample processing, which is described here. 8 (This article does not deal with the overall functionality of the 9 EMU10K1 chips. See the manuals section for further details.) 10 11 The ALSA driver programs this portion of chip by default code 12 (can be altered later) which offers the following functionality: 13 14 15 IEC958 (S/PDIF) raw PCM 16 ======================= 17 18 This PCM device (it's the 3rd PCM device (index 2!) and first subdevice 19 (index 0) for a given card) allows to forward 48kHz, stereo, 16-bit 20 little endian streams without any modifications to the digital output 21 (coaxial or optical). The universal interface allows the creation of up 22 to 8 raw PCM devices operating at 48kHz, 16-bit little endian. It would 23 be easy to add support for multichannel devices to the current code, 24 but the conversion routines exist only for stereo (2-channel streams) 25 at the time. 26 27 Look to tram_poke routines in lowlevel/emu10k1/emufx.c for more details. 28 29 30 Digital mixer controls 31 ====================== 32 33 These controls are built using the DSP instructions. They offer extended 34 functionality. Only the default built-in code in the ALSA driver is described 35 here. Note that the controls work as attenuators: the maximum value is the 36 neutral position leaving the signal unchanged. Note that if the same destination 37 is mentioned in multiple controls, the signal is accumulated and can be clipped 38 (set to maximal or minimal value without checking for overflow). 39 40 41 Explanation of used abbreviations: 42 43 DAC 44 digital to analog converter 45 ADC 46 analog to digital converter 47 I2S 48 one-way three wire serial bus for digital sound by Philips Semiconductors 49 (this standard is used for connecting standalone D/A and A/D converters) 50 LFE 51 low frequency effects (used as subwoofer signal) 52 AC97 53 a chip containing an analog mixer, D/A and A/D converters 54 IEC958 55 S/PDIF 56 FX-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 --------------------------------------- 64 This control is used to attenuate samples from left and right PCM FX-bus 65 accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 66 The result samples are forwarded to the front DAC PCM slots of the AC97 codec. 67 68 ``name='Wave Surround Playback Volume',index=0`` 69 ------------------------------------------------ 70 This control is used to attenuate samples from left and right PCM FX-bus 71 accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 72 The result samples are forwarded to the rear I2S DACs. These DACs operates 73 separately (they are not inside the AC97 codec). 74 75 ``name='Wave Center Playback Volume',index=0`` 76 ---------------------------------------------- 77 This control is used to attenuate samples from left and right PCM FX-bus 78 accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 79 The result is mixed to mono signal (single channel) and forwarded to 80 the ??rear?? right DAC PCM slot of the AC97 codec. 81 82 ``name='Wave LFE Playback Volume',index=0`` 83 ------------------------------------------- 84 This control is used to attenuate samples from left and right PCM FX-bus 85 accumulators. ALSA uses accumulators 0 and 1 for left and right PCM. 86 The result is mixed to mono signal (single channel) and forwarded to 87 the ??rear?? left DAC PCM slot of the AC97 codec. 88 89 ``name='Wave Capture Volume',index=0``, ``name='Wave Capture Switch',index=0`` 90 ------------------------------------------------------------------------------ 91 These controls are used to attenuate samples from left and right PCM FX-bus 92 accumulator. ALSA uses accumulators 0 and 1 for left and right PCM. 93 The result is forwarded to the ADC capture FIFO (thus to the standard capture 94 PCM device). 95 96 ``name='Synth Playback Volume',index=0`` 97 ---------------------------------------- 98 This control is used to attenuate samples from left and right MIDI FX-bus 99 accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples. 100 The 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 -------------------------------------------------------------------------------- 104 These controls are used to attenuate samples from left and right MIDI FX-bus 105 accumulator. ALSA uses accumulators 4 and 5 for left and right MIDI samples. 106 The result is forwarded to the ADC capture FIFO (thus to the standard capture 107 PCM device). 108 109 ``name='Surround Playback Volume',index=0`` 110 ------------------------------------------- 111 This control is used to attenuate samples from left and right rear PCM FX-bus 112 accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples. 113 The result samples are forwarded to the rear I2S DACs. These DACs operate 114 separately (they are not inside the AC97 codec). 115 116 ``name='Surround Capture Volume',index=0``, ``name='Surround Capture Switch',index=0`` 117 -------------------------------------------------------------------------------------- 118 These controls are used to attenuate samples from left and right rear PCM FX-bus 119 accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples. 120 The result is forwarded to the ADC capture FIFO (thus to the standard capture 121 PCM device). 122 123 ``name='Center Playback Volume',index=0`` 124 ----------------------------------------- 125 This control is used to attenuate sample for center PCM FX-bus accumulator. 126 ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded 127 to the ??rear?? right DAC PCM slot of the AC97 codec. 128 129 ``name='LFE Playback Volume',index=0`` 130 -------------------------------------- 131 This control is used to attenuate sample for center PCM FX-bus accumulator. 132 ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded 133 to the ??rear?? left DAC PCM slot of the AC97 codec. 134 135 ``name='AC97 Playback Volume',index=0`` 136 --------------------------------------- 137 This control is used to attenuate samples from left and right front ADC PCM slots 138 of the AC97 codec. The result samples are forwarded to the front DAC PCM 139 slots 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 -------------------------------------- 148 This control is used to attenuate samples from left and right front ADC PCM slots 149 of the AC97 codec. The result is forwarded to the ADC capture FIFO (thus to 150 the 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 --------------------------------------------- 158 This control is used to attenuate samples from left and right IEC958 TTL 159 digital inputs (usually used by a CDROM drive). The result samples are 160 forwarded to the front DAC PCM slots of the AC97 codec. 161 162 ``name='IEC958 TTL Capture Volume',index=0`` 163 -------------------------------------------- 164 This control is used to attenuate samples from left and right IEC958 TTL 165 digital inputs (usually used by a CDROM drive). The result samples are 166 forwarded to the ADC capture FIFO (thus to the standard capture PCM device). 167 168 ``name='Zoom Video Playback Volume',index=0`` 169 --------------------------------------------- 170 This control is used to attenuate samples from left and right zoom video 171 digital inputs (usually used by a CDROM drive). The result samples are 172 forwarded to the front DAC PCM slots of the AC97 codec. 173 174 ``name='Zoom Video Capture Volume',index=0`` 175 -------------------------------------------- 176 This control is used to attenuate samples from left and right zoom video 177 digital inputs (usually used by a CDROM drive). The result samples are 178 forwarded to the ADC capture FIFO (thus to the standard capture PCM device). 179 180 ``name='IEC958 LiveDrive Playback Volume',index=0`` 181 --------------------------------------------------- 182 This control is used to attenuate samples from left and right IEC958 optical 183 digital input. The result samples are forwarded to the front DAC PCM slots 184 of the AC97 codec. 185 186 ``name='IEC958 LiveDrive Capture Volume',index=0`` 187 -------------------------------------------------- 188 This control is used to attenuate samples from left and right IEC958 optical 189 digital 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 ------------------------------------------------- 194 This control is used to attenuate samples from left and right IEC958 coaxial 195 digital inputs. The result samples are forwarded to the front DAC PCM slots 196 of the AC97 codec. 197 198 ``name='IEC958 Coaxial Capture Volume',index=0`` 199 ------------------------------------------------ 200 This control is used to attenuate samples from left and right IEC958 coaxial 201 digital 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 ---------------------------------------------------------------------------------------------------- 206 This control is used to attenuate samples from left and right I2S ADC 207 inputs (on the LiveDrive). The result samples are forwarded to the front 208 DAC PCM slots of the AC97 codec. 209 210 ``name='Line LiveDrive Capture Volume',index=1``, ``name='Line LiveDrive Capture Volume',index=1`` 211 -------------------------------------------------------------------------------------------------- 212 This control is used to attenuate samples from left and right I2S ADC 213 inputs (on the LiveDrive). The result samples are forwarded to the ADC 214 capture FIFO (thus to the standard capture PCM device). 215 216 ``name='Tone Control - Switch',index=0`` 217 ---------------------------------------- 218 This control turns the tone control on or off. The samples for front, rear 219 and center / LFE outputs are affected. 220 221 ``name='Tone Control - Bass',index=0`` 222 -------------------------------------- 223 This control sets the bass intensity. There is no neutral value!! 224 When the tone control code is activated, the samples are always modified. 225 The closest value to pure signal is 20. 226 227 ``name='Tone Control - Treble',index=0`` 228 ---------------------------------------- 229 This control sets the treble intensity. There is no neutral value!! 230 When the tone control code is activated, the samples are always modified. 231 The closest value to pure signal is 20. 232 233 ``name='IEC958 Optical Raw Playback Switch',index=0`` 234 ----------------------------------------------------- 235 If this switch is on, then the samples for the IEC958 (S/PDIF) digital 236 output are taken only from the raw FX8010 PCM, otherwise standard front 237 PCM samples are taken. 238 239 ``name='Headphone Playback Volume',index=1`` 240 -------------------------------------------- 241 This control attenuates the samples for the headphone output. 242 243 ``name='Headphone Center Playback Switch',index=1`` 244 --------------------------------------------------- 245 If this switch is on, then the sample for the center PCM is put to the 246 left headphone output (useful for SB Live cards without separate center/LFE 247 output). 248 249 ``name='Headphone LFE Playback Switch',index=1`` 250 ------------------------------------------------ 251 If this switch is on, then the sample for the center PCM is put to the 252 right headphone output (useful for SB Live cards without separate center/LFE 253 output). 254 255 256 PCM stream related controls 257 =========================== 258 259 ``name='EMU10K1 PCM Volume',index 0-31`` 260 ---------------------------------------- 261 Channel volume attenuation in range 0-0x1fffd. The middle value (no 262 attenuation) is default. The channel mapping for three values is 263 as 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 ---------------------------------------------- 271 This control specifies the destination - FX-bus accumulators. There are 272 twelve 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 3 286 287 Don't forget that it's illegal to assign a channel to the same FX-bus accumulator 288 more than once (it means 0=0 && 1=0 is an invalid combination). 289 290 ``name='EMU10K1 PCM Send Volume',index 0-31`` 291 --------------------------------------------- 292 It specifies the attenuation (amount) for given destination in range 0-255. 293 The 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) 307 308 309 310 MANUALS/PATENTS 311 =============== 312 313 ftp://opensource.creative.com/pub/doc 314 ------------------------------------- 315 316 Note that the site is defunct, but the documents are available 317 from various other locations. 318 319 LM4545.pdf 320 AC97 Codec 321 m2049.pdf 322 The EMU10K1 Digital Audio Processor 323 hog63.ps 324 FX8010 - A DSP Chip Architecture for Audio Effects 325 326 327 WIPO Patents 328 ------------ 329 330 WO 9901813 (A1) 331 Audio Effects Processor with multiple asynchronous streams 332 (Jan. 14, 1999) 333 334 WO 9901814 (A1) 335 Processor with Instruction Set for Audio Effects (Jan. 14, 1999) 336 337 WO 9901953 (A1) 338 Audio Effects Processor having Decoupled Instruction 339 Execution and Audio Data Sequencing (Jan. 14, 1999) 340 341 342 US Patents (https://www.uspto.gov/) 343 ----------------------------------- 344 345 US 5925841 346 Digital Sampling Instrument employing cache memory (Jul. 20, 1999) 347 348 US 5928342 349 Audio Effects Processor integrated on a single chip 350 with a multiport memory onto which multiple asynchronous 351 digital sound samples can be concurrently loaded 352 (Jul. 27, 1999) 353 354 US 5930158 355 Processor with Instruction Set for Audio Effects (Jul. 27, 1999) 356 357 US 6032235 358 Memory initialization circuit (Tram) (Feb. 29, 2000) 359 360 US 6138207 361 Interpolation looping of audio samples in cache connected to 362 system bus with prioritization and modification of bus transfers 363 in accordance with loop ends and minimum block sizes 364 (Oct. 24, 2000) 365 366 US 6151670 367 Method for conserving memory storage using a 368 pool of short term memory registers 369 (Nov. 21, 2000) 370 371 US 6195715 372 Interrupt control for multiple programs communicating with 373 a common interrupt by associating programs to GP registers, 374 defining interrupt register, polling GP registers, and invoking 375 callback routine associated with defined interrupt register 376 (Feb. 27, 2001)
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