1 // license:BSD-3-Clause
2 // copyright-holders:Derrick Renaud
3 /***************************************************************************
4 polepos.c
5 Sound handler
6 ****************************************************************************/
7 #include "emu.h"
8 #include "polepos.h"
9
10 #include "namco52.h"
11 #include "namco54.h"
12
13 #include "machine/rescap.h"
14
15
16 #define OUTPUT_RATE 24000
17
18 #define POLEPOS_R166 1000.0
19 #define POLEPOS_R167 2200.0
20 #define POLEPOS_R168 4700.0
21
22 /* resistor values when shorted by 4066 running at 5V */
23 #define POLEPOS_R166_SHUNT 1.0/(1.0/POLEPOS_R166 + 1.0/250)
24 #define POLEPOS_R167_SHUNT 1.0/(1.0/POLEPOS_R166 + 1.0/250)
25 #define POLEPOS_R168_SHUNT 1.0/(1.0/POLEPOS_R166 + 1.0/250)
26
27 static const double volume_table[8] =
28 {
29 (POLEPOS_R168_SHUNT + POLEPOS_R167_SHUNT + POLEPOS_R166_SHUNT + 2200) / 10000,
30 (POLEPOS_R168_SHUNT + POLEPOS_R167_SHUNT + POLEPOS_R166 + 2200) / 10000,
31 (POLEPOS_R168_SHUNT + POLEPOS_R167 + POLEPOS_R166_SHUNT + 2200) / 10000,
32 (POLEPOS_R168_SHUNT + POLEPOS_R167 + POLEPOS_R166 + 2200) / 10000,
33 (POLEPOS_R168 + POLEPOS_R167_SHUNT + POLEPOS_R166_SHUNT + 2200) / 10000,
34 (POLEPOS_R168 + POLEPOS_R167_SHUNT + POLEPOS_R166 + 2200) / 10000,
35 (POLEPOS_R168 + POLEPOS_R167 + POLEPOS_R166_SHUNT + 2200) / 10000,
36 (POLEPOS_R168 + POLEPOS_R167 + POLEPOS_R166 + 2200) / 10000
37 };
38
39 static const double r_filt_out[3] = {RES_K(4.7), RES_K(7.5), RES_K(10)};
40 static const double r_filt_total = 1.0 / (1.0/RES_K(4.7) + 1.0/RES_K(7.5) + 1.0/RES_K(10));
41
42 /* Max filter order */
43 #define FILTER_ORDER_MAX 51
44
45 /* Define to use integer calculation */
46 #define FILTER_USE_INT
47
48 #ifdef FILTER_USE_INT
49 typedef int filter_real;
50 #define FILTER_INT_FRACT 15 /* fractional bits */
51 #else
52 typedef double filter_real;
53 #endif
54
55 struct filter
56 {
57 filter_real xcoeffs[(FILTER_ORDER_MAX+1)/2];
58 unsigned order;
59 };
60
61 struct filter_state
62 {
63 unsigned prev_mac;
64 filter_real xprev[FILTER_ORDER_MAX];
65 };
66
67 /* Filter types */
68 #define FILTER_LOWPASS 0
69 #define FILTER_HIGHPASS 1
70 #define FILTER_BANDPASS 2
71
72 #define Q_TO_DAMP(q) (1.0/q)
73
74
75 /* Setup the filter context based on the passed filter type info.
76 * type - 1 of the 3 defined filter types
77 * fc - center frequency
78 * d - damp = 1/Q
79 * gain - overall filter gain. Set to 1 if not needed.
80 */
setup(device_t * device,int type,double fc,double d,double gain)81 void polepos_sound_device::filter2_context::setup(device_t *device, int type, double fc, double d, double gain)
82 {
83 int const sample_rate = device->machine().sample_rate();
84 double const two_over_T = 2*sample_rate;
85 double const two_over_T_squared = two_over_T * two_over_T;
86
87 /* calculate digital filter coefficents */
88 /* cutoff freq, in radians/sec */
89 /*w = 2.0*M_PI*fc; no pre-warping */
90 double const w = sample_rate*2.0*tan(M_PI*fc/sample_rate); /* pre-warping */
91 double const w_squared = w*w;
92
93 /* temp variable */
94 double const den = two_over_T_squared + d*w*two_over_T + w_squared;
95
96 a1 = 2.0*(-two_over_T_squared + w_squared)/den;
97 a2 = (two_over_T_squared - d*w*two_over_T + w_squared)/den;
98
99 switch (type)
100 {
101 case FILTER_LOWPASS:
102 b0 = b2 = w_squared/den;
103 b1 = 2.0*(b0);
104 break;
105 case FILTER_BANDPASS:
106 b0 = d*w*two_over_T/den;
107 b1 = 0.0;
108 b2 = -(b0);
109 break;
110 case FILTER_HIGHPASS:
111 b0 = b2 = two_over_T_squared/den;
112 b1 = -2.0*(b0);
113 break;
114 default:
115 device->logerror("filter2_setup() - Invalid filter type for 2nd order filter.");
116 break;
117 }
118
119 b0 *= gain;
120 b1 *= gain;
121 b2 *= gain;
122 }
123
124
125 /* Reset the input/output voltages to 0. */
reset()126 void polepos_sound_device::filter2_context::reset()
127 {
128 x0 = 0;
129 x1 = 0;
130 x2 = 0;
131 y0 = 0;
132 y1 = 0;
133 y2 = 0;
134 }
135
136
137 /* Step the filter.
138 * x0 is the new input, which needs to be set before stepping.
139 * y0 is the new filter output.
140 */
step()141 void polepos_sound_device::filter2_context::step()
142 {
143 y0 = -a1 * y1 - a2 * y2 + b0 * x0 + b1 * x1 + b2 * x2;
144 x2 = x1;
145 x1 = x0;
146 y2 = y1;
147 y1 = y0;
148 }
149
150
151 /* Setup a filter2 structure based on an op-amp multipole bandpass circuit.
152 * NOTE: If r2 is not used then set to 0.
153 * vRef is not needed to setup filter.
154 *
155 * .--------+---------.
156 * | | |
157 * --- c1 Z |
158 * --- Z r3 |
159 * | Z |
160 * r1 | c2 | |\ |
161 * In >----ZZZZ----+---------+--||----+ | \ |
162 * Z '--|- \ |
163 * Z r2 | >--+------> out
164 * Z .--|+ /
165 * | | | /
166 * gnd vRef >---' |/
167 *
168 */
opamp_m_bandpass_setup(device_t * device,double r1,double r2,double r3,double c1,double c2)169 void polepos_sound_device::filter2_context::opamp_m_bandpass_setup(device_t *device, double r1, double r2, double r3, double c1, double c2)
170 {
171 if (r1 == 0)
172 {
173 device->logerror("filter_opamp_m_bandpass_setup() - r1 can not be 0");
174 return; /* Filter can not be setup. Undefined results. */
175 }
176
177 double r_in, gain;
178
179 if (r2 == 0)
180 {
181 gain = 1;
182 r_in = r1;
183 }
184 else
185 {
186 gain = r2 / (r1 + r2);
187 r_in = 1.0 / (1.0/r1 + 1.0/r2);
188 }
189
190 double const fc = 1.0 / (2 * M_PI * sqrt(r_in * r3 * c1 * c2));
191 double const d = (c1 + c2) / sqrt(r3 / r_in * c1 * c2);
192 gain *= -r3 / r_in * c2 / (c1 + c2);
193
194 setup(device, FILTER_BANDPASS, fc, d, gain);
195 }
196
197
198 // device type definition
199 DEFINE_DEVICE_TYPE(POLEPOS_SOUND, polepos_sound_device, "polepos_sound", "Pole Position Custom Sound")
200
201
202 //**************************************************************************
203 // LIVE DEVICE
204 //**************************************************************************
205
206 //-------------------------------------------------
207 // polepos_sound_device - constructor
208 //-------------------------------------------------
209
polepos_sound_device(const machine_config & mconfig,const char * tag,device_t * owner,uint32_t clock)210 polepos_sound_device::polepos_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
211 : device_t(mconfig, POLEPOS_SOUND, tag, owner, clock),
212 device_sound_interface(mconfig, *this),
213 m_current_position(0),
214 m_sample_msb(0),
215 m_sample_lsb(0),
216 m_sample_enable(0),
217 m_stream(nullptr)
218 {
219 }
220
221
222 //-------------------------------------------------
223 // device_start - device-specific startup
224 //-------------------------------------------------
225
device_start()226 void polepos_sound_device::device_start()
227 {
228 m_stream = stream_alloc(0, 1, OUTPUT_RATE);
229 m_sample_msb = m_sample_lsb = 0;
230 m_sample_enable = 0;
231
232 /* setup the filters */
233 m_filter_engine[0].opamp_m_bandpass_setup(this, RES_K(220), RES_K(33), RES_K(390), CAP_U(.01), CAP_U(.01));
234 m_filter_engine[1].opamp_m_bandpass_setup(this, RES_K(150), RES_K(22), RES_K(330), CAP_U(.0047), CAP_U(.0047));
235 /* Filter 3 is a little different. Because of the input capacitor, it is
236 * a high pass filter. */
237 m_filter_engine[2].setup(this, FILTER_HIGHPASS, 950, Q_TO_DAMP(.707), 1);
238 }
239
240
241 //-------------------------------------------------
242 // device_reset - device-specific reset
243 //-------------------------------------------------
244
device_reset()245 void polepos_sound_device::device_reset()
246 {
247 int loop;
248 for (loop = 0; loop < 3; loop++)
249 m_filter_engine[loop].reset();
250 }
251
252
253 //-------------------------------------------------
254 // sound_stream_update - handle a stream update
255 //-------------------------------------------------
256
sound_stream_update(sound_stream & stream,std::vector<read_stream_view> const & inputs,std::vector<write_stream_view> & outputs)257 void polepos_sound_device::sound_stream_update(sound_stream &stream, std::vector<read_stream_view> const &inputs, std::vector<write_stream_view> &outputs)
258 {
259 uint32_t step, clock, slot;
260 uint8_t *base;
261 double volume, i_total;
262 auto &buffer = outputs[0];
263 int loop;
264
265 /* if we're not enabled, just fill with 0 */
266 if (!m_sample_enable)
267 {
268 buffer.fill(0);
269 return;
270 }
271
272 /* determine the effective clock rate */
273 clock = (unscaled_clock() / 16) * ((m_sample_msb + 1) * 64 + m_sample_lsb + 1) / (64*64);
274 step = (clock << 12) / OUTPUT_RATE;
275
276 /* determine the volume */
277 slot = (m_sample_msb >> 3) & 7;
278 volume = volume_table[slot];
279 base = &machine().root_device().memregion("engine")->base()[slot * 0x800];
280
281 /* fill in the sample */
282 for (int sampindex = 0; sampindex < buffer.samples(); sampindex++)
283 {
284 m_filter_engine[0].x0 = (3.4 / 255 * base[(m_current_position >> 12) & 0x7ff] - 2) * volume;
285 m_filter_engine[1].x0 = m_filter_engine[0].x0;
286 m_filter_engine[2].x0 = m_filter_engine[0].x0;
287
288 i_total = 0;
289 for (loop = 0; loop < 3; loop++)
290 {
291 m_filter_engine[loop].step();
292 /* The op-amp powered @ 5V will clip to 0V & 3.5V.
293 * Adjusted to vRef of 2V, we will clip as follows: */
294 if (m_filter_engine[loop].y0 > 1.5) m_filter_engine[loop].y0 = 1.5;
295 if (m_filter_engine[loop].y0 < -2) m_filter_engine[loop].y0 = -2;
296
297 i_total += m_filter_engine[loop].y0 / r_filt_out[loop];
298 }
299 i_total *= r_filt_total/2; /* now contains voltage adjusted by final gain */
300
301 buffer.put(sampindex, i_total);
302 m_current_position += step;
303 }
304 }
305
306
WRITE_LINE_MEMBER(polepos_sound_device::clson_w)307 WRITE_LINE_MEMBER(polepos_sound_device::clson_w)
308 {
309 if (!state)
310 {
311 polepos_engine_sound_lsb_w(0);
312 polepos_engine_sound_msb_w(0);
313 }
314 }
315
316
317 /************************************/
318 /* Write LSB of engine sound */
319 /************************************/
polepos_engine_sound_lsb_w(uint8_t data)320 void polepos_sound_device::polepos_engine_sound_lsb_w(uint8_t data)
321 {
322 /* Update stream first so all samples at old frequency are updated. */
323 m_stream->update();
324 m_sample_lsb = data & 62;
325 m_sample_enable = data & 1;
326 }
327
328 /************************************/
329 /* Write MSB of engine sound */
330 /************************************/
polepos_engine_sound_msb_w(uint8_t data)331 void polepos_sound_device::polepos_engine_sound_msb_w(uint8_t data)
332 {
333 m_stream->update();
334 m_sample_msb = data & 63;
335 }
336
337
338 /*************************************
339 *
340 * Pole Position
341 *
342 * Discrete sound emulation: Feb 2007, D.R.
343 *
344 *************************************/
345
346 /* nodes - sounds */
347 #define POLEPOS_CHANL1_SND NODE_11
348 #define POLEPOS_CHANL2_SND NODE_12
349 #define POLEPOS_CHANL3_SND NODE_13
350 #define POLEPOS_CHANL4_SND NODE_14
351
352 #define POLEPOS_54XX_DAC_R (1.0 / (1.0 / RES_K(47) + 1.0 / RES_K(22) + 1.0 / RES_K(10) + 1.0 / RES_K(4.7)))
353 static const discrete_dac_r1_ladder polepos_54xx_dac =
354 {
355 4, /* number of DAC bits */
356 /* 54XX_0 54XX_1 54XX_2 */
357 { RES_K(47), /* R124, R136, R152 */
358 RES_K(22), /* R120, R132, R142 */
359 RES_K(10), /* R119, R131, R138 */
360 RES_K(4.7)}, /* R118, R126, R103 */
361 0, 0, 0, 0 /* nothing extra */
362 };
363
364 #define POLEPOS_52XX_DAC_R (1.0 / (1.0 / RES_K(100) + 1.0 / RES_K(47) + 1.0 / RES_K(22) + 1.0 / RES_K(10)))
365 static const discrete_dac_r1_ladder polepos_52xx_dac =
366 {
367 4, /* number of DAC bits */
368 { RES_K(100), /* R160 */
369 RES_K(47), /* R159 */
370 RES_K(22), /* R155 */
371 RES_K(10)}, /* R154 */
372 0, 0, 0, 0 /* nothing extra */
373 };
374
375 /* R117 R116 R117 */
376 #define POLEPOS_VREF (5.0 * (RES_K(1) / (RES_K(1.5) + RES_K(1))))
377
378 static const discrete_op_amp_filt_info polepos_chanl1_filt =
379 {
380 POLEPOS_54XX_DAC_R + RES_K(22), /* R121 */
381 0, /* no second input */
382 RES_K(12), /* R125 */
383 0, /* not used */
384 RES_K(120), /* R122 */
385 CAP_U(0.0022), /* C27 */
386 CAP_U(0.0022), /* C28 */
387 0, /* not used */
388 POLEPOS_VREF, /* vRef */
389 5, /* vP */
390 0 /* vN */
391 };
392
393 static const discrete_op_amp_filt_info polepos_chanl2_filt =
394 {
395 POLEPOS_54XX_DAC_R + RES_K(15), /* R133 */
396 0, /* no second input */
397 RES_K(15), /* R137 */
398 0, /* not used */
399 RES_K(120), /* R134 */
400 CAP_U(0.022), /* C29 */
401 CAP_U(0.022), /* C30 */
402 0, /* not used */
403 POLEPOS_VREF, /* vRef */
404 5, /* vP */
405 0 /* vN */
406 };
407
408 static const discrete_op_amp_filt_info polepos_chanl3_filt =
409 {
410 POLEPOS_54XX_DAC_R + RES_K(22), /* R139 */
411 0, /* no second input */
412 RES_K(22), /* R143 */
413 0, /* not used */
414 RES_K(180), /* R140 */
415 CAP_U(0.047), /* C33 */
416 CAP_U(0.047), /* C34 */
417 0, /* not used */
418 POLEPOS_VREF, /* vRef */
419 5, /* vP */
420 0 /* vN */
421 };
422
423
424 DISCRETE_SOUND_START(polepos_discrete)
425
426 /************************************************
427 * Input register mapping
428 ************************************************/
429 DISCRETE_INPUT_DATA(NAMCO_54XX_0_DATA(NODE_01))
430 DISCRETE_INPUT_DATA(NAMCO_54XX_1_DATA(NODE_01))
431 DISCRETE_INPUT_DATA(NAMCO_54XX_2_DATA(NODE_01))
432 DISCRETE_INPUT_DATA(NAMCO_52XX_P_DATA(NODE_04))
433
434 /************************************************
435 * CHANL1 sound
436 ************************************************/
437 DISCRETE_DAC_R1(NODE_20,
438 NAMCO_54XX_2_DATA(NODE_01),
439 4, /* 4V - unmeasured*/
440 &polepos_54xx_dac)
441 DISCRETE_OP_AMP_FILTER(NODE_21,
442 1, /* ENAB */
443 NODE_20, /* INP0 */
444 0, /* INP1 - not used */
445 DISC_OP_AMP_FILTER_IS_BAND_PASS_1M, &polepos_chanl1_filt)
446 /* fake it so 0 is now vRef */
447 DISCRETE_ADDER2(POLEPOS_CHANL1_SND,
448 1, /* ENAB */
449 NODE_21, -POLEPOS_VREF)
450
451 /************************************************
452 * CHANL2 sound
453 ************************************************/
454 DISCRETE_DAC_R1(NODE_30,
455 NAMCO_54XX_1_DATA(NODE_01),
456 4, /* 4V - unmeasured*/
457 &polepos_54xx_dac)
458 DISCRETE_OP_AMP_FILTER(NODE_31,
459 1, /* ENAB */
460 NODE_30, /* INP0 */
461 0, /* INP1 - not used */
462 DISC_OP_AMP_FILTER_IS_BAND_PASS_1M, &polepos_chanl2_filt)
463 /* fake it so 0 is now vRef */
464 DISCRETE_ADDER2(POLEPOS_CHANL2_SND,
465 1, /* ENAB */
466 NODE_31, -POLEPOS_VREF)
467
468 /************************************************
469 * CHANL3 sound
470 ************************************************/
471 DISCRETE_DAC_R1(NODE_40,
472 NAMCO_54XX_0_DATA(NODE_01),
473 4, /* 4V - unmeasured*/
474 &polepos_54xx_dac)
475 DISCRETE_OP_AMP_FILTER(NODE_41,
476 1, /* ENAB */
477 NODE_40, /* INP0 */
478 0, /* INP1 - not used */
479 DISC_OP_AMP_FILTER_IS_BAND_PASS_1M, &polepos_chanl3_filt)
480 /* fake it so 0 is now vRef */
481 DISCRETE_ADDER2(POLEPOS_CHANL3_SND,
482 1, /* ENAB */
483 NODE_41, -POLEPOS_VREF)
484
485 /************************************************
486 * CHANL4 sound
487 ************************************************/
488 /* this circuit was simulated in SPICE and an equivalent filter circuit generated */
489 DISCRETE_DAC_R1(NODE_50,
490 NAMCO_52XX_P_DATA(NODE_04),
491 4, /* 4V - unmeasured*/
492 &polepos_52xx_dac)
493 /* fake it so 0 is now vRef */
494 DISCRETE_ADDER2(NODE_51,
495 1, /* ENAB */
496 NODE_50, -POLEPOS_VREF)
497 DISCRETE_FILTER2(NODE_52,
498 1, /* ENAB */
499 NODE_51, /* INP0 */
500 100, /* FREQ */
501 1.0 / 0.3, /* DAMP */
502 DISC_FILTER_HIGHPASS)
503 DISCRETE_FILTER2(NODE_53,
504 1, /* ENAB */
505 NODE_52, /* INP0 */
506 1200, /* FREQ */
507 1.0 / 0.8, /* DAMP */
508 DISC_FILTER_LOWPASS)
509 DISCRETE_GAIN(NODE_54,
510 NODE_53, /* IN0 */
511 0.5 /* overall filter GAIN */)
512 /* clamp to the maximum of the op-amp shifted by vRef */
513 DISCRETE_CLAMP(POLEPOS_CHANL4_SND,
514 NODE_54, /* IN0 */
515 0, /* MIN */
516 5.0 - OP_AMP_VP_RAIL_OFFSET - POLEPOS_VREF) /* MAX */
517
518 /************************************************
519 * Output
520 ************************************************/
521 DISCRETE_OUTPUT(POLEPOS_CHANL1_SND, 32767/2)
522 DISCRETE_OUTPUT(POLEPOS_CHANL2_SND, 32767/2)
523 DISCRETE_OUTPUT(POLEPOS_CHANL3_SND, 32767/2)
524 DISCRETE_OUTPUT(POLEPOS_CHANL4_SND, 32767/2)
525 DISCRETE_SOUND_END
526