1=============================================
2Sound Blaster Audigy mixer / default DSP code
3=============================================
4
5This is based on sb-live-mixer.rst.
6
7The EMU10K2 chips have a DSP part which can be programmed to support
8various ways of sample processing, which is described here.
9(This article does not deal with the overall functionality of the
10EMU10K2 chips. See the manuals section for further details.)
11
12The ALSA driver programs this portion of chip by default code
13(can be altered later) which offers the following functionality:
14
15
16Digital mixer controls
17======================
18
19These controls are built using the DSP instructions. They offer extended
20functionality. Only the default built-in code in the ALSA driver is described
21here. Note that the controls work as attenuators: the maximum value is the
22neutral position leaving the signal unchanged. Note that if the same destination
23is mentioned in multiple controls, the signal is accumulated and can be clipped
24(set to maximal or minimal value without checking for overflow).
25
26
27Explanation of used abbreviations:
28
29DAC
30	digital to analog converter
31ADC
32	analog to digital converter
33I2S
34	one-way three wire serial bus for digital sound by Philips Semiconductors
35	(this standard is used for connecting standalone D/A and A/D converters)
36LFE
37	low frequency effects (used as subwoofer signal)
38AC97
39	a chip containing an analog mixer, D/A and A/D converters
40IEC958
41	S/PDIF
42FX-bus
43	the EMU10K2 chip has an effect bus containing 64 accumulators.
44	Each of the synthesizer voices can feed its output to these accumulators
45	and the DSP microcontroller can operate with the resulting sum.
46
47name='PCM Front Playback Volume',index=0
48----------------------------------------
49This control is used to attenuate samples for left and right front PCM FX-bus
50accumulators. ALSA uses accumulators 8 and 9 for left and right front PCM
51samples for 5.1 playback. The result samples are forwarded to the front DAC PCM
52slots of the Philips DAC.
53
54name='PCM Surround Playback Volume',index=0
55-------------------------------------------
56This control is used to attenuate samples for left and right surround PCM FX-bus
57accumulators. ALSA uses accumulators 2 and 3 for left and right surround PCM
58samples for 5.1 playback. The result samples are forwarded to the surround DAC PCM
59slots of the Philips DAC.
60
61name='PCM Center Playback Volume',index=0
62-----------------------------------------
63This control is used to attenuate samples for center PCM FX-bus accumulator.
64ALSA uses accumulator 6 for center PCM sample for 5.1 playback. The result sample
65is forwarded to the center DAC PCM slot of the Philips DAC.
66
67name='PCM LFE Playback Volume',index=0
68--------------------------------------
69This control is used to attenuate sample for LFE PCM FX-bus accumulator.
70ALSA uses accumulator 7 for LFE PCM sample for 5.1 playback. The result sample
71is forwarded to the LFE DAC PCM slot of the Philips DAC.
72
73name='PCM Playback Volume',index=0
74----------------------------------
75This control is used to attenuate samples for left and right PCM FX-bus
76accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples for
77stereo playback. The result samples are forwarded to the front DAC PCM slots
78of the Philips DAC.
79
80name='PCM Capture Volume',index=0
81---------------------------------
82This control is used to attenuate samples for left and right PCM FX-bus
83accumulator. ALSA uses accumulators 0 and 1 for left and right PCM.
84The result is forwarded to the ADC capture FIFO (thus to the standard capture
85PCM device).
86
87name='Music Playback Volume',index=0
88------------------------------------
89This control is used to attenuate samples for left and right MIDI FX-bus
90accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples.
91The result samples are forwarded to the front DAC PCM slots of the AC97 codec.
92
93name='Music Capture Volume',index=0
94-----------------------------------
95These controls are used to attenuate samples for left and right MIDI FX-bus
96accumulator. ALSA uses accumulators 4 and 5 for left and right PCM.
97The result is forwarded to the ADC capture FIFO (thus to the standard capture
98PCM device).
99
100name='Mic Playback Volume',index=0
101----------------------------------
102This control is used to attenuate samples for left and right Mic input.
103For Mic input is used AC97 codec. The result samples are forwarded to
104the front DAC PCM slots of the Philips DAC. Samples are forwarded to Mic
105capture FIFO (device 1 - 16bit/8KHz mono) too without volume control.
106
107name='Mic Capture Volume',index=0
108---------------------------------
109This control is used to attenuate samples for left and right Mic input.
110The result is forwarded to the ADC capture FIFO (thus to the standard capture
111PCM device).
112
113name='Audigy CD Playback Volume',index=0
114----------------------------------------
115This control is used to attenuate samples from left and right IEC958 TTL
116digital inputs (usually used by a CDROM drive). The result samples are
117forwarded to the front DAC PCM slots of the Philips DAC.
118
119name='Audigy CD Capture Volume',index=0
120---------------------------------------
121This control is used to attenuate samples from left and right IEC958 TTL
122digital inputs (usually used by a CDROM drive). The result samples are
123forwarded to the ADC capture FIFO (thus to the standard capture PCM device).
124
125name='IEC958 Optical Playback Volume',index=0
126---------------------------------------------
127This control is used to attenuate samples from left and right IEC958 optical
128digital input. The result samples are forwarded to the front DAC PCM slots
129of the Philips DAC.
130
131name='IEC958 Optical Capture Volume',index=0
132--------------------------------------------
133This control is used to attenuate samples from left and right IEC958 optical
134digital inputs. The result samples are forwarded to the ADC capture FIFO
135(thus to the standard capture PCM device).
136
137name='Line2 Playback Volume',index=0
138------------------------------------
139This control is used to attenuate samples from left and right I2S ADC
140inputs (on the AudigyDrive). The result samples are forwarded to the front
141DAC PCM slots of the Philips DAC.
142
143name='Line2 Capture Volume',index=1
144-----------------------------------
145This control is used to attenuate samples from left and right I2S ADC
146inputs (on the AudigyDrive). The result samples are forwarded to the ADC
147capture FIFO (thus to the standard capture PCM device).
148
149name='Analog Mix Playback Volume',index=0
150-----------------------------------------
151This control is used to attenuate samples from left and right I2S ADC
152inputs from Philips ADC. The result samples are forwarded to the front
153DAC PCM slots of the Philips DAC. This contains mix from analog sources
154like CD, Line In, Aux, ....
155
156name='Analog Mix Capture Volume',index=1
157----------------------------------------
158This control is used to attenuate samples from left and right I2S ADC
159inputs Philips ADC. The result samples are forwarded to the ADC
160capture FIFO (thus to the standard capture PCM device).
161
162name='Aux2 Playback Volume',index=0
163-----------------------------------
164This control is used to attenuate samples from left and right I2S ADC
165inputs (on the AudigyDrive). The result samples are forwarded to the front
166DAC PCM slots of the Philips DAC.
167
168name='Aux2 Capture Volume',index=1
169----------------------------------
170This control is used to attenuate samples from left and right I2S ADC
171inputs (on the AudigyDrive). The result samples are forwarded to the ADC
172capture FIFO (thus to the standard capture PCM device).
173
174name='Front Playback Volume',index=0
175------------------------------------
176All stereo signals are mixed together and mirrored to surround, center and LFE.
177This control is used to attenuate samples for left and right front speakers of
178this mix.
179
180name='Surround Playback Volume',index=0
181---------------------------------------
182All stereo signals are mixed together and mirrored to surround, center and LFE.
183This control is used to attenuate samples for left and right surround speakers of
184this mix.
185
186name='Center Playback Volume',index=0
187-------------------------------------
188All stereo signals are mixed together and mirrored to surround, center and LFE.
189This control is used to attenuate sample for center speaker of this mix.
190
191name='LFE Playback Volume',index=0
192----------------------------------
193All stereo signals are mixed together and mirrored to surround, center and LFE.
194This control is used to attenuate sample for LFE speaker of this mix.
195
196name='Tone Control - Switch',index=0
197------------------------------------
198This control turns the tone control on or off. The samples for front, rear
199and center / LFE outputs are affected.
200
201name='Tone Control - Bass',index=0
202----------------------------------
203This control sets the bass intensity. There is no neutral value!!
204When the tone control code is activated, the samples are always modified.
205The closest value to pure signal is 20.
206
207name='Tone Control - Treble',index=0
208------------------------------------
209This control sets the treble intensity. There is no neutral value!!
210When the tone control code is activated, the samples are always modified.
211The closest value to pure signal is 20.
212
213name='Master Playback Volume',index=0
214-------------------------------------
215This control is used to attenuate samples for front, surround, center and
216LFE outputs.
217
218name='IEC958 Optical Raw Playback Switch',index=0
219-------------------------------------------------
220If this switch is on, then the samples for the IEC958 (S/PDIF) digital
221output are taken only from the raw iec958 ALSA PCM device (which uses
222accumulators 20 and 21 for left and right PCM by default).
223
224
225PCM stream related controls
226===========================
227
228name='EMU10K1 PCM Volume',index 0-31
229------------------------------------
230Channel volume attenuation in range 0-0xffff. The maximum value (no
231attenuation) is default. The channel mapping for three values is
232as follows:
233
234* 0 - mono, default 0xffff (no attenuation)
235* 1 - left, default 0xffff (no attenuation)
236* 2 - right, default 0xffff (no attenuation)
237
238name='EMU10K1 PCM Send Routing',index 0-31
239------------------------------------------
240This control specifies the destination - FX-bus accumulators. There are 24
241values in this mapping:
242
243* 0 -  mono, A destination (FX-bus 0-63), default 0
244* 1 -  mono, B destination (FX-bus 0-63), default 1
245* 2 -  mono, C destination (FX-bus 0-63), default 2
246* 3 -  mono, D destination (FX-bus 0-63), default 3
247* 4 -  mono, E destination (FX-bus 0-63), default 0
248* 5 -  mono, F destination (FX-bus 0-63), default 0
249* 6 -  mono, G destination (FX-bus 0-63), default 0
250* 7 -  mono, H destination (FX-bus 0-63), default 0
251* 8 -  left, A destination (FX-bus 0-63), default 0
252* 9 -  left, B destination (FX-bus 0-63), default 1
253* 10 -  left, C destination (FX-bus 0-63), default 2
254* 11 -  left, D destination (FX-bus 0-63), default 3
255* 12 -  left, E destination (FX-bus 0-63), default 0
256* 13 -  left, F destination (FX-bus 0-63), default 0
257* 14 -  left, G destination (FX-bus 0-63), default 0
258* 15 -  left, H destination (FX-bus 0-63), default 0
259* 16 - right, A destination (FX-bus 0-63), default 0
260* 17 - right, B destination (FX-bus 0-63), default 1
261* 18 - right, C destination (FX-bus 0-63), default 2
262* 19 - right, D destination (FX-bus 0-63), default 3
263* 20 - right, E destination (FX-bus 0-63), default 0
264* 21 - right, F destination (FX-bus 0-63), default 0
265* 22 - right, G destination (FX-bus 0-63), default 0
266* 23 - right, H destination (FX-bus 0-63), default 0
267
268Don't forget that it's illegal to assign a channel to the same FX-bus accumulator
269more than once (it means 0=0 && 1=0 is an invalid combination).
270
271name='EMU10K1 PCM Send Volume',index 0-31
272-----------------------------------------
273It specifies the attenuation (amount) for given destination in range 0-255.
274The channel mapping is following:
275
276*  0 -  mono, A destination attn, default 255 (no attenuation)
277*  1 -  mono, B destination attn, default 255 (no attenuation)
278*  2 -  mono, C destination attn, default 0 (mute)
279*  3 -  mono, D destination attn, default 0 (mute)
280*  4 -  mono, E destination attn, default 0 (mute)
281*  5 -  mono, F destination attn, default 0 (mute)
282*  6 -  mono, G destination attn, default 0 (mute)
283*  7 -  mono, H destination attn, default 0 (mute)
284*  8 -  left, A destination attn, default 255 (no attenuation)
285*  9 -  left, B destination attn, default 0 (mute)
286* 10 -  left, C destination attn, default 0 (mute)
287* 11 -  left, D destination attn, default 0 (mute)
288* 12 -  left, E destination attn, default 0 (mute)
289* 13 -  left, F destination attn, default 0 (mute)
290* 14 -  left, G destination attn, default 0 (mute)
291* 15 -  left, H destination attn, default 0 (mute)
292* 16 - right, A destination attn, default 0 (mute)
293* 17 - right, B destination attn, default 255 (no attenuation)
294* 18 - right, C destination attn, default 0 (mute)
295* 19 - right, D destination attn, default 0 (mute)
296* 20 - right, E destination attn, default 0 (mute)
297* 21 - right, F destination attn, default 0 (mute)
298* 22 - right, G destination attn, default 0 (mute)
299* 23 - right, H destination attn, default 0 (mute)
300
301
302
303MANUALS/PATENTS
304===============
305
306ftp://opensource.creative.com/pub/doc
307-------------------------------------
308
309Note that the site is defunct, but the documents are available
310from various other locations.
311
312LM4545.pdf
313	AC97 Codec
314
315m2049.pdf
316	The EMU10K1 Digital Audio Processor
317
318hog63.ps
319	FX8010 - A DSP Chip Architecture for Audio Effects
320
321
322WIPO Patents
323------------
324
325WO 9901813 (A1)
326	Audio Effects Processor with multiple asynchronous streams
327	(Jan. 14, 1999)
328
329WO 9901814 (A1)
330	Processor with Instruction Set for Audio Effects (Jan. 14, 1999)
331
332WO 9901953 (A1)
333	Audio Effects Processor having Decoupled Instruction
334        Execution and Audio Data Sequencing (Jan. 14, 1999)
335
336
337US Patents (https://www.uspto.gov/)
338-----------------------------------
339
340US 5925841
341	Digital Sampling Instrument employing cache memory (Jul. 20, 1999)
342
343US 5928342
344	Audio Effects Processor integrated on a single chip
345        with a multiport memory onto which multiple asynchronous
346        digital sound samples can be concurrently loaded
347	(Jul. 27, 1999)
348
349US 5930158
350	Processor with Instruction Set for Audio Effects (Jul. 27, 1999)
351
352US 6032235
353	Memory initialization circuit (Tram) (Feb. 29, 2000)
354
355US 6138207
356	Interpolation looping of audio samples in cache connected to
357        system bus with prioritization and modification of bus transfers
358        in accordance with loop ends and minimum block sizes
359	(Oct. 24, 2000)
360
361US 6151670
362	Method for conserving memory storage using a
363        pool of  short term memory registers
364	(Nov. 21, 2000)
365
366US 6195715
367	Interrupt control for multiple programs communicating with
368        a common interrupt by associating programs to GP registers,
369        defining interrupt register, polling GP registers, and invoking
370        callback routine associated with defined interrupt register
371	(Feb. 27, 2001)
372