1 2 Sound 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 14 151) IEC958 (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 29 302) Digital 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 - digital to analog converter 44ADC - analog to digital converter 45I2S - one-way three wire serial bus for digital sound by Philips Semiconductors 46 (this standard is used for connecting standalone DAC and ADC converters) 47LFE - low frequency effects (subwoofer signal) 48AC97 - a chip containing an analog mixer, DAC and ADC converters 49IEC958 - S/PDIF 50FX-bus - the EMU10K1 chip has an effect bus containing 16 accumulators. 51 Each of the synthesizer voices can feed its output to these accumulators 52 and the DSP microcontroller can operate with the resulting sum. 53 54 55name='Wave Playback Volume',index=0 56 57This control is used to attenuate samples for left and right PCM FX-bus 58accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 59The result samples are forwarded to the front DAC PCM slots of the AC97 codec. 60 61name='Wave Surround Playback Volume',index=0 62 63This control is used to attenuate samples for left and right PCM FX-bus 64accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples. 65The result samples are forwarded to the rear I2S DACs. These DACs operates 66separately (they are not inside the AC97 codec). 67 68name='Wave Center 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 is mixed to mono signal (single channel) and forwarded to 73the ??rear?? right DAC PCM slot of the AC97 codec. 74 75name='Wave LFE 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. 79The result is mixed to mono signal (single channel) and forwarded to 80the ??rear?? left DAC PCM slot of the AC97 codec. 81 82name='Wave Capture Volume',index=0 83name='Wave Capture Switch',index=0 84 85These controls are used to attenuate samples for left and right PCM FX-bus 86accumulator. ALSA uses accumulators 0 and 1 for left and right PCM. 87The result is forwarded to the ADC capture FIFO (thus to the standard capture 88PCM device). 89 90name='Synth Playback Volume',index=0 91 92This control is used to attenuate samples for left and right MIDI FX-bus 93accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples. 94The result samples are forwarded to the front DAC PCM slots of the AC97 codec. 95 96name='Synth Capture Volume',index=0 97name='Synth Capture Switch',index=0 98 99These controls are used to attenuate samples for left and right MIDI FX-bus 100accumulator. ALSA uses accumulators 4 and 5 for left and right PCM. 101The result is forwarded to the ADC capture FIFO (thus to the standard capture 102PCM device). 103 104name='Surround Playback Volume',index=0 105 106This control is used to attenuate samples for left and right rear PCM FX-bus 107accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples. 108The result samples are forwarded to the rear I2S DACs. These DACs operate 109separately (they are not inside the AC97 codec). 110 111name='Surround Capture Volume',index=0 112name='Surround Capture Switch',index=0 113 114These controls are used to attenuate samples for left and right rear PCM FX-bus 115accumulators. ALSA uses accumulators 2 and 3 for left and right rear PCM samples. 116The result is forwarded to the ADC capture FIFO (thus to the standard capture 117PCM device). 118 119name='Center Playback Volume',index=0 120 121This control is used to attenuate sample for center PCM FX-bus accumulator. 122ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded 123to the ??rear?? right DAC PCM slot of the AC97 codec. 124 125name='LFE Playback Volume',index=0 126 127This control is used to attenuate sample for center PCM FX-bus accumulator. 128ALSA uses accumulator 6 for center PCM sample. The result sample is forwarded 129to the ??rear?? left DAC PCM slot of the AC97 codec. 130 131name='AC97 Playback Volume',index=0 132 133This control is used to attenuate samples for left and right front ADC PCM slots 134of the AC97 codec. The result samples are forwarded to the front DAC PCM 135slots of the AC97 codec. 136******************************************************************************** 137*** Note: This control should be zero for the standard operations, otherwise *** 138*** a digital loopback is activated. *** 139******************************************************************************** 140 141name='AC97 Capture Volume',index=0 142 143This control is used to attenuate samples for left and right front ADC PCM slots 144of the AC97 codec. The result is forwarded to the ADC capture FIFO (thus to 145the standard capture PCM device). 146******************************************************************************** 147*** Note: This control should be 100 (maximal value), otherwise no analog *** 148*** inputs of the AC97 codec can be captured (recorded). *** 149******************************************************************************** 150 151name='IEC958 TTL Playback Volume',index=0 152 153This control is used to attenuate samples from left and right IEC958 TTL 154digital inputs (usually used by a CDROM drive). The result samples are 155forwarded to the front DAC PCM slots of the AC97 codec. 156 157name='IEC958 TTL Capture Volume',index=0 158 159This control is used to attenuate samples from left and right IEC958 TTL 160digital inputs (usually used by a CDROM drive). The result samples are 161forwarded to the ADC capture FIFO (thus to the standard capture PCM device). 162 163name='Zoom Video Playback Volume',index=0 164 165This control is used to attenuate samples from left and right zoom video 166digital inputs (usually used by a CDROM drive). The result samples are 167forwarded to the front DAC PCM slots of the AC97 codec. 168 169name='Zoom Video Capture Volume',index=0 170 171This control is used to attenuate samples from left and right zoom video 172digital inputs (usually used by a CDROM drive). The result samples are 173forwarded to the ADC capture FIFO (thus to the standard capture PCM device). 174 175name='IEC958 LiveDrive Playback Volume',index=0 176 177This control is used to attenuate samples from left and right IEC958 optical 178digital input. The result samples are forwarded to the front DAC PCM slots 179of the AC97 codec. 180 181name='IEC958 LiveDrive Capture Volume',index=0 182 183This control is used to attenuate samples from left and right IEC958 optical 184digital inputs. The result samples are forwarded to the ADC capture FIFO 185(thus to the standard capture PCM device). 186 187name='IEC958 Coaxial Playback Volume',index=0 188 189This control is used to attenuate samples from left and right IEC958 coaxial 190digital inputs. The result samples are forwarded to the front DAC PCM slots 191of the AC97 codec. 192 193name='IEC958 Coaxial Capture Volume',index=0 194 195This control is used to attenuate samples from left and right IEC958 coaxial 196digital inputs. The result samples are forwarded to the ADC capture FIFO 197(thus to the standard capture PCM device). 198 199name='Line LiveDrive Playback Volume',index=0 200name='Line LiveDrive Playback Volume',index=1 201 202This control is used to attenuate samples from left and right I2S ADC 203inputs (on the LiveDrive). The result samples are forwarded to the front 204DAC PCM slots of the AC97 codec. 205 206name='Line LiveDrive Capture Volume',index=1 207name='Line LiveDrive Capture Volume',index=1 208 209This control is used to attenuate samples from left and right I2S ADC 210inputs (on the LiveDrive). The result samples are forwarded to the ADC 211capture FIFO (thus to the standard capture PCM device). 212 213name='Tone Control - Switch',index=0 214 215This control turns the tone control on or off. The samples for front, rear 216and center / LFE outputs are affected. 217 218name='Tone Control - Bass',index=0 219 220This control sets the bass intensity. There is no neutral value!! 221When the tone control code is activated, the samples are always modified. 222The closest value to pure signal is 20. 223 224name='Tone Control - Treble',index=0 225 226This control sets the treble intensity. There is no neutral value!! 227When the tone control code is activated, the samples are always modified. 228The closest value to pure signal is 20. 229 230name='IEC958 Optical Raw Playback Switch',index=0 231 232If this switch is on, then the samples for the IEC958 (S/PDIF) digital 233output are taken only from the raw FX8010 PCM, otherwise standard front 234PCM samples are taken. 235 236name='Headphone Playback Volume',index=1 237 238This control attenuates the samples for the headphone output. 239 240name='Headphone Center Playback Switch',index=1 241 242If this switch is on, then the sample for the center PCM is put to the 243left headphone output (useful for SB Live cards without separate center/LFE 244output). 245 246name='Headphone LFE Playback Switch',index=1 247 248If this switch is on, then the sample for the center PCM is put to the 249right headphone output (useful for SB Live cards without separate center/LFE 250output). 251 252 2533) PCM stream related controls 254------------------------------ 255 256name='EMU10K1 PCM Volume',index 0-31 257 258Channel volume attenuation in range 0-0xffff. The maximum value (no 259attenuation) is default. The channel mapping for three values is 260as follows: 261 262 0 - mono, default 0xffff (no attenuation) 263 1 - left, default 0xffff (no attenuation) 264 2 - right, default 0xffff (no attenuation) 265 266name='EMU10K1 PCM Send Routing',index 0-31 267 268This control specifies the destination - FX-bus accumulators. There are 269twelve values with this mapping: 270 271 0 - mono, A destination (FX-bus 0-15), default 0 272 1 - mono, B destination (FX-bus 0-15), default 1 273 2 - mono, C destination (FX-bus 0-15), default 2 274 3 - mono, D destination (FX-bus 0-15), default 3 275 4 - left, A destination (FX-bus 0-15), default 0 276 5 - left, B destination (FX-bus 0-15), default 1 277 6 - left, C destination (FX-bus 0-15), default 2 278 7 - left, D destination (FX-bus 0-15), default 3 279 8 - right, A destination (FX-bus 0-15), default 0 280 9 - right, B destination (FX-bus 0-15), default 1 281 10 - right, C destination (FX-bus 0-15), default 2 282 11 - right, D destination (FX-bus 0-15), default 3 283 284Don't forget that it's illegal to assign a channel to the same FX-bus accumulator 285more than once (it means 0=0 && 1=0 is an invalid combination). 286 287name='EMU10K1 PCM Send Volume',index 0-31 288 289It specifies the attenuation (amount) for given destination in range 0-255. 290The channel mapping is following: 291 292 0 - mono, A destination attn, default 255 (no attenuation) 293 1 - mono, B destination attn, default 255 (no attenuation) 294 2 - mono, C destination attn, default 0 (mute) 295 3 - mono, D destination attn, default 0 (mute) 296 4 - left, A destination attn, default 255 (no attenuation) 297 5 - left, B destination attn, default 0 (mute) 298 6 - left, C destination attn, default 0 (mute) 299 7 - left, D destination attn, default 0 (mute) 300 8 - right, A destination attn, default 0 (mute) 301 9 - right, B destination attn, default 255 (no attenuation) 302 10 - right, C destination attn, default 0 (mute) 303 11 - right, D destination attn, default 0 (mute) 304 305 306 3074) MANUALS/PATENTS: 308------------------- 309 310ftp://opensource.creative.com/pub/doc 311------------------------------------- 312 313 Files: 314 LM4545.pdf AC97 Codec 315 316 m2049.pdf The EMU10K1 Digital Audio Processor 317 318 hog63.ps FX8010 - A DSP Chip Architecture for Audio Effects 319 320 321WIPO Patents 322------------ 323 Patent numbers: 324 WO 9901813 (A1) Audio Effects Processor with multiple asynchronous (Jan. 14, 1999) 325 streams 326 327 WO 9901814 (A1) Processor with Instruction Set for Audio Effects (Jan. 14, 1999) 328 329 WO 9901953 (A1) Audio Effects Processor having Decoupled Instruction 330 Execution and Audio Data Sequencing (Jan. 14, 1999) 331 332 333US Patents (http://www.uspto.gov/) 334---------------------------------- 335 336 US 5925841 Digital Sampling Instrument employing cache memory (Jul. 20, 1999) 337 338 US 5928342 Audio Effects Processor integrated on a single chip (Jul. 27, 1999) 339 with a multiport memory onto which multiple asynchronous 340 digital sound samples can be concurrently loaded 341 342 US 5930158 Processor with Instruction Set for Audio Effects (Jul. 27, 1999) 343 344 US 6032235 Memory initialization circuit (Tram) (Feb. 29, 2000) 345 346 US 6138207 Interpolation looping of audio samples in cache connected to (Oct. 24, 2000) 347 system bus with prioritization and modification of bus transfers 348 in accordance with loop ends and minimum block sizes 349 350 US 6151670 Method for conserving memory storage using a (Nov. 21, 2000) 351 pool of short term memory registers 352 353 US 6195715 Interrupt control for multiple programs communicating with (Feb. 27, 2001) 354 a common interrupt by associating programs to GP registers, 355 defining interrupt register, polling GP registers, and invoking 356 callback routine associated with defined interrupt register 357