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1 | /***************************************************************************** |
2 | * Copyright 2003 - 2008 Broadcom Corporation. All rights reserved. | |
3 | * | |
4 | * Unless you and Broadcom execute a separate written software license | |
5 | * agreement governing use of this software, this software is licensed to you | |
6 | * under the terms of the GNU General Public License version 2, available at | |
7 | * http://www.broadcom.com/licenses/GPLv2.php (the "GPL"). | |
8 | * | |
9 | * Notwithstanding the above, under no circumstances may you combine this | |
10 | * software in any way with any other Broadcom software provided under a | |
11 | * license other than the GPL, without Broadcom's express prior written | |
12 | * consent. | |
13 | *****************************************************************************/ | |
14 | ||
15 | /****************************************************************************/ | |
16 | /** | |
17 | * @file tmrHw.c | |
18 | * | |
19 | * @brief Low level Timer driver routines | |
20 | * | |
21 | * @note | |
22 | * | |
23 | * These routines provide basic timer functionality only. | |
24 | */ | |
25 | /****************************************************************************/ | |
26 | ||
27 | /* ---- Include Files ---------------------------------------------------- */ | |
28 | ||
29 | #include <csp/errno.h> | |
30 | #include <csp/stdint.h> | |
31 | ||
32 | #include <csp/tmrHw.h> | |
33 | #include <mach/csp/tmrHw_reg.h> | |
34 | ||
35 | #define tmrHw_ASSERT(a) if (!(a)) *(char *)0 = 0 | |
36 | #define tmrHw_MILLISEC_PER_SEC (1000) | |
37 | ||
38 | #define tmrHw_LOW_1_RESOLUTION_COUNT (tmrHw_LOW_RESOLUTION_CLOCK / tmrHw_MILLISEC_PER_SEC) | |
39 | #define tmrHw_LOW_1_MAX_MILLISEC (0xFFFFFFFF / tmrHw_LOW_1_RESOLUTION_COUNT) | |
40 | #define tmrHw_LOW_16_RESOLUTION_COUNT (tmrHw_LOW_1_RESOLUTION_COUNT / 16) | |
41 | #define tmrHw_LOW_16_MAX_MILLISEC (0xFFFFFFFF / tmrHw_LOW_16_RESOLUTION_COUNT) | |
42 | #define tmrHw_LOW_256_RESOLUTION_COUNT (tmrHw_LOW_1_RESOLUTION_COUNT / 256) | |
43 | #define tmrHw_LOW_256_MAX_MILLISEC (0xFFFFFFFF / tmrHw_LOW_256_RESOLUTION_COUNT) | |
44 | ||
45 | #define tmrHw_HIGH_1_RESOLUTION_COUNT (tmrHw_HIGH_RESOLUTION_CLOCK / tmrHw_MILLISEC_PER_SEC) | |
46 | #define tmrHw_HIGH_1_MAX_MILLISEC (0xFFFFFFFF / tmrHw_HIGH_1_RESOLUTION_COUNT) | |
47 | #define tmrHw_HIGH_16_RESOLUTION_COUNT (tmrHw_HIGH_1_RESOLUTION_COUNT / 16) | |
48 | #define tmrHw_HIGH_16_MAX_MILLISEC (0xFFFFFFFF / tmrHw_HIGH_16_RESOLUTION_COUNT) | |
49 | #define tmrHw_HIGH_256_RESOLUTION_COUNT (tmrHw_HIGH_1_RESOLUTION_COUNT / 256) | |
50 | #define tmrHw_HIGH_256_MAX_MILLISEC (0xFFFFFFFF / tmrHw_HIGH_256_RESOLUTION_COUNT) | |
51 | ||
52 | static void ResetTimer(tmrHw_ID_t timerId) | |
53 | __attribute__ ((section(".aramtext"))); | |
54 | static int tmrHw_divide(int num, int denom) | |
55 | __attribute__ ((section(".aramtext"))); | |
56 | ||
57 | /****************************************************************************/ | |
58 | /** | |
59 | * @brief Get timer capability | |
60 | * | |
61 | * This function returns various capabilities/attributes of a timer | |
62 | * | |
63 | * @return Capability | |
64 | * | |
65 | */ | |
66 | /****************************************************************************/ | |
67 | uint32_t tmrHw_getTimerCapability(tmrHw_ID_t timerId, /* [ IN ] Timer Id */ | |
68 | tmrHw_CAPABILITY_e capability /* [ IN ] Timer capability */ | |
69 | ) { | |
70 | switch (capability) { | |
71 | case tmrHw_CAPABILITY_CLOCK: | |
72 | return (timerId <= | |
73 | 1) ? tmrHw_LOW_RESOLUTION_CLOCK : | |
74 | tmrHw_HIGH_RESOLUTION_CLOCK; | |
75 | case tmrHw_CAPABILITY_RESOLUTION: | |
76 | return 32; | |
77 | default: | |
78 | return 0; | |
79 | } | |
80 | return 0; | |
81 | } | |
82 | ||
83 | /****************************************************************************/ | |
84 | /** | |
85 | * @brief Resets a timer | |
86 | * | |
87 | * This function initializes timer | |
88 | * | |
89 | * @return void | |
90 | * | |
91 | */ | |
92 | /****************************************************************************/ | |
93 | static void ResetTimer(tmrHw_ID_t timerId /* [ IN ] Timer Id */ | |
94 | ) { | |
95 | /* Reset timer */ | |
96 | pTmrHw[timerId].LoadValue = 0; | |
97 | pTmrHw[timerId].CurrentValue = 0xFFFFFFFF; | |
98 | pTmrHw[timerId].Control = 0; | |
99 | pTmrHw[timerId].BackgroundLoad = 0; | |
100 | /* Always configure as a 32 bit timer */ | |
101 | pTmrHw[timerId].Control |= tmrHw_CONTROL_32BIT; | |
102 | /* Clear interrupt only if raw status interrupt is set */ | |
103 | if (pTmrHw[timerId].RawInterruptStatus) { | |
104 | pTmrHw[timerId].InterruptClear = 0xFFFFFFFF; | |
105 | } | |
106 | } | |
107 | ||
108 | /****************************************************************************/ | |
109 | /** | |
110 | * @brief Sets counter value for an interval in ms | |
111 | * | |
112 | * @return On success: Effective counter value set | |
113 | * On failure: 0 | |
114 | * | |
115 | */ | |
116 | /****************************************************************************/ | |
117 | static tmrHw_INTERVAL_t SetTimerPeriod(tmrHw_ID_t timerId, /* [ IN ] Timer Id */ | |
118 | tmrHw_INTERVAL_t msec /* [ IN ] Interval in milli-second */ | |
119 | ) { | |
120 | uint32_t scale = 0; | |
121 | uint32_t count = 0; | |
122 | ||
123 | if (timerId == 0 || timerId == 1) { | |
124 | if (msec <= tmrHw_LOW_1_MAX_MILLISEC) { | |
125 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1; | |
126 | scale = tmrHw_LOW_1_RESOLUTION_COUNT; | |
127 | } else if (msec <= tmrHw_LOW_16_MAX_MILLISEC) { | |
128 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_16; | |
129 | scale = tmrHw_LOW_16_RESOLUTION_COUNT; | |
130 | } else if (msec <= tmrHw_LOW_256_MAX_MILLISEC) { | |
131 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_256; | |
132 | scale = tmrHw_LOW_256_RESOLUTION_COUNT; | |
133 | } else { | |
134 | return 0; | |
135 | } | |
136 | ||
137 | count = msec * scale; | |
138 | /* Set counter value */ | |
139 | pTmrHw[timerId].LoadValue = count; | |
140 | pTmrHw[timerId].BackgroundLoad = count; | |
141 | ||
142 | } else if (timerId == 2 || timerId == 3) { | |
143 | if (msec <= tmrHw_HIGH_1_MAX_MILLISEC) { | |
144 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1; | |
145 | scale = tmrHw_HIGH_1_RESOLUTION_COUNT; | |
146 | } else if (msec <= tmrHw_HIGH_16_MAX_MILLISEC) { | |
147 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_16; | |
148 | scale = tmrHw_HIGH_16_RESOLUTION_COUNT; | |
149 | } else if (msec <= tmrHw_HIGH_256_MAX_MILLISEC) { | |
150 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_256; | |
151 | scale = tmrHw_HIGH_256_RESOLUTION_COUNT; | |
152 | } else { | |
153 | return 0; | |
154 | } | |
155 | ||
156 | count = msec * scale; | |
157 | /* Set counter value */ | |
158 | pTmrHw[timerId].LoadValue = count; | |
159 | pTmrHw[timerId].BackgroundLoad = count; | |
160 | } | |
161 | return count / scale; | |
162 | } | |
163 | ||
164 | /****************************************************************************/ | |
165 | /** | |
166 | * @brief Configures a periodic timer in terms of timer interrupt rate | |
167 | * | |
168 | * This function initializes a periodic timer to generate specific number of | |
169 | * timer interrupt per second | |
170 | * | |
171 | * @return On success: Effective timer frequency | |
172 | * On failure: 0 | |
173 | * | |
174 | */ | |
175 | /****************************************************************************/ | |
176 | tmrHw_RATE_t tmrHw_setPeriodicTimerRate(tmrHw_ID_t timerId, /* [ IN ] Timer Id */ | |
177 | tmrHw_RATE_t rate /* [ IN ] Number of timer interrupt per second */ | |
178 | ) { | |
179 | uint32_t resolution = 0; | |
180 | uint32_t count = 0; | |
181 | ResetTimer(timerId); | |
182 | ||
183 | /* Set timer mode periodic */ | |
184 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PERIODIC; | |
185 | pTmrHw[timerId].Control &= ~tmrHw_CONTROL_ONESHOT; | |
186 | /* Set timer in highest resolution */ | |
187 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1; | |
188 | ||
189 | if (rate && (timerId == 0 || timerId == 1)) { | |
190 | if (rate > tmrHw_LOW_RESOLUTION_CLOCK) { | |
191 | return 0; | |
192 | } | |
193 | resolution = tmrHw_LOW_RESOLUTION_CLOCK; | |
194 | } else if (rate && (timerId == 2 || timerId == 3)) { | |
195 | if (rate > tmrHw_HIGH_RESOLUTION_CLOCK) { | |
196 | return 0; | |
197 | } else { | |
198 | resolution = tmrHw_HIGH_RESOLUTION_CLOCK; | |
199 | } | |
200 | } else { | |
201 | return 0; | |
202 | } | |
203 | /* Find the counter value */ | |
204 | count = resolution / rate; | |
205 | /* Set counter value */ | |
206 | pTmrHw[timerId].LoadValue = count; | |
207 | pTmrHw[timerId].BackgroundLoad = count; | |
208 | ||
209 | return resolution / count; | |
210 | } | |
211 | ||
212 | /****************************************************************************/ | |
213 | /** | |
214 | * @brief Configures a periodic timer to generate timer interrupt after | |
215 | * certain time interval | |
216 | * | |
217 | * This function initializes a periodic timer to generate timer interrupt | |
218 | * after every time interval in millisecond | |
219 | * | |
220 | * @return On success: Effective interval set in milli-second | |
221 | * On failure: 0 | |
222 | * | |
223 | */ | |
224 | /****************************************************************************/ | |
225 | tmrHw_INTERVAL_t tmrHw_setPeriodicTimerInterval(tmrHw_ID_t timerId, /* [ IN ] Timer Id */ | |
226 | tmrHw_INTERVAL_t msec /* [ IN ] Interval in milli-second */ | |
227 | ) { | |
228 | ResetTimer(timerId); | |
229 | ||
230 | /* Set timer mode periodic */ | |
231 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PERIODIC; | |
232 | pTmrHw[timerId].Control &= ~tmrHw_CONTROL_ONESHOT; | |
233 | ||
234 | return SetTimerPeriod(timerId, msec); | |
235 | } | |
236 | ||
237 | /****************************************************************************/ | |
238 | /** | |
239 | * @brief Configures a periodic timer to generate timer interrupt just once | |
240 | * after certain time interval | |
241 | * | |
242 | * This function initializes a periodic timer to generate a single ticks after | |
243 | * certain time interval in millisecond | |
244 | * | |
245 | * @return On success: Effective interval set in milli-second | |
246 | * On failure: 0 | |
247 | * | |
248 | */ | |
249 | /****************************************************************************/ | |
250 | tmrHw_INTERVAL_t tmrHw_setOneshotTimerInterval(tmrHw_ID_t timerId, /* [ IN ] Timer Id */ | |
251 | tmrHw_INTERVAL_t msec /* [ IN ] Interval in milli-second */ | |
252 | ) { | |
253 | ResetTimer(timerId); | |
254 | ||
255 | /* Set timer mode oneshot */ | |
256 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PERIODIC; | |
257 | pTmrHw[timerId].Control |= tmrHw_CONTROL_ONESHOT; | |
258 | ||
259 | return SetTimerPeriod(timerId, msec); | |
260 | } | |
261 | ||
262 | /****************************************************************************/ | |
263 | /** | |
264 | * @brief Configures a timer to run as a free running timer | |
265 | * | |
266 | * This function initializes a timer to run as a free running timer | |
267 | * | |
268 | * @return Timer resolution (count / sec) | |
269 | * | |
270 | */ | |
271 | /****************************************************************************/ | |
272 | tmrHw_RATE_t tmrHw_setFreeRunningTimer(tmrHw_ID_t timerId, /* [ IN ] Timer Id */ | |
273 | uint32_t divider /* [ IN ] Dividing the clock frequency */ | |
274 | ) { | |
275 | uint32_t scale = 0; | |
276 | ||
277 | ResetTimer(timerId); | |
278 | /* Set timer as free running mode */ | |
279 | pTmrHw[timerId].Control &= ~tmrHw_CONTROL_PERIODIC; | |
280 | pTmrHw[timerId].Control &= ~tmrHw_CONTROL_ONESHOT; | |
281 | ||
282 | if (divider >= 64) { | |
283 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_256; | |
284 | scale = 256; | |
285 | } else if (divider >= 8) { | |
286 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_16; | |
287 | scale = 16; | |
288 | } else { | |
289 | pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1; | |
290 | scale = 1; | |
291 | } | |
292 | ||
293 | if (timerId == 0 || timerId == 1) { | |
294 | return tmrHw_divide(tmrHw_LOW_RESOLUTION_CLOCK, scale); | |
295 | } else if (timerId == 2 || timerId == 3) { | |
296 | return tmrHw_divide(tmrHw_HIGH_RESOLUTION_CLOCK, scale); | |
297 | } | |
298 | ||
299 | return 0; | |
300 | } | |
301 | ||
302 | /****************************************************************************/ | |
303 | /** | |
304 | * @brief Starts a timer | |
305 | * | |
306 | * This function starts a preconfigured timer | |
307 | * | |
308 | * @return -1 - On Failure | |
309 | * 0 - On Success | |
310 | * | |
311 | */ | |
312 | /****************************************************************************/ | |
313 | int tmrHw_startTimer(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
314 | ) { | |
315 | pTmrHw[timerId].Control |= tmrHw_CONTROL_TIMER_ENABLE; | |
316 | return 0; | |
317 | } | |
318 | ||
319 | /****************************************************************************/ | |
320 | /** | |
321 | * @brief Stops a timer | |
322 | * | |
323 | * This function stops a running timer | |
324 | * | |
325 | * @return -1 - On Failure | |
326 | * 0 - On Success | |
327 | * | |
328 | */ | |
329 | /****************************************************************************/ | |
330 | int tmrHw_stopTimer(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
331 | ) { | |
332 | pTmrHw[timerId].Control &= ~tmrHw_CONTROL_TIMER_ENABLE; | |
333 | return 0; | |
334 | } | |
335 | ||
336 | /****************************************************************************/ | |
337 | /** | |
338 | * @brief Gets current timer count | |
339 | * | |
340 | * This function returns the current timer value | |
341 | * | |
342 | * @return Current downcounting timer value | |
343 | * | |
344 | */ | |
345 | /****************************************************************************/ | |
346 | uint32_t tmrHw_GetCurrentCount(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
347 | ) { | |
348 | /* return 32 bit timer value */ | |
349 | switch (pTmrHw[timerId].Control & tmrHw_CONTROL_MODE_MASK) { | |
350 | case tmrHw_CONTROL_FREE_RUNNING: | |
351 | if (pTmrHw[timerId].CurrentValue) { | |
352 | return tmrHw_MAX_COUNT - pTmrHw[timerId].CurrentValue; | |
353 | } | |
354 | break; | |
355 | case tmrHw_CONTROL_PERIODIC: | |
356 | case tmrHw_CONTROL_ONESHOT: | |
357 | return pTmrHw[timerId].BackgroundLoad - | |
358 | pTmrHw[timerId].CurrentValue; | |
359 | } | |
360 | return 0; | |
361 | } | |
362 | ||
363 | /****************************************************************************/ | |
364 | /** | |
365 | * @brief Gets timer count rate | |
366 | * | |
367 | * This function returns the number of counts per second | |
368 | * | |
369 | * @return Count rate | |
370 | * | |
371 | */ | |
372 | /****************************************************************************/ | |
373 | tmrHw_RATE_t tmrHw_getCountRate(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
374 | ) { | |
375 | uint32_t divider = 0; | |
376 | ||
377 | switch (pTmrHw[timerId].Control & tmrHw_CONTROL_PRESCALE_MASK) { | |
378 | case tmrHw_CONTROL_PRESCALE_1: | |
379 | divider = 1; | |
380 | break; | |
381 | case tmrHw_CONTROL_PRESCALE_16: | |
382 | divider = 16; | |
383 | break; | |
384 | case tmrHw_CONTROL_PRESCALE_256: | |
385 | divider = 256; | |
386 | break; | |
387 | default: | |
388 | tmrHw_ASSERT(0); | |
389 | } | |
390 | ||
391 | if (timerId == 0 || timerId == 1) { | |
392 | return tmrHw_divide(tmrHw_LOW_RESOLUTION_CLOCK, divider); | |
393 | } else { | |
394 | return tmrHw_divide(tmrHw_HIGH_RESOLUTION_CLOCK, divider); | |
395 | } | |
396 | return 0; | |
397 | } | |
398 | ||
399 | /****************************************************************************/ | |
400 | /** | |
401 | * @brief Enables timer interrupt | |
402 | * | |
403 | * This function enables the timer interrupt | |
404 | * | |
405 | * @return N/A | |
406 | * | |
407 | */ | |
408 | /****************************************************************************/ | |
409 | void tmrHw_enableInterrupt(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
410 | ) { | |
411 | pTmrHw[timerId].Control |= tmrHw_CONTROL_INTERRUPT_ENABLE; | |
412 | } | |
413 | ||
414 | /****************************************************************************/ | |
415 | /** | |
416 | * @brief Disables timer interrupt | |
417 | * | |
418 | * This function disable the timer interrupt | |
419 | * | |
420 | * @return N/A | |
421 | * | |
422 | */ | |
423 | /****************************************************************************/ | |
424 | void tmrHw_disableInterrupt(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
425 | ) { | |
426 | pTmrHw[timerId].Control &= ~tmrHw_CONTROL_INTERRUPT_ENABLE; | |
427 | } | |
428 | ||
429 | /****************************************************************************/ | |
430 | /** | |
431 | * @brief Clears the interrupt | |
432 | * | |
433 | * This function clears the timer interrupt | |
434 | * | |
435 | * @return N/A | |
436 | * | |
437 | * @note | |
438 | * Must be called under the context of ISR | |
439 | */ | |
440 | /****************************************************************************/ | |
441 | void tmrHw_clearInterrupt(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
442 | ) { | |
443 | pTmrHw[timerId].InterruptClear = 0x1; | |
444 | } | |
445 | ||
446 | /****************************************************************************/ | |
447 | /** | |
448 | * @brief Gets the interrupt status | |
449 | * | |
450 | * This function returns timer interrupt status | |
451 | * | |
452 | * @return Interrupt status | |
453 | */ | |
454 | /****************************************************************************/ | |
455 | tmrHw_INTERRUPT_STATUS_e tmrHw_getInterruptStatus(tmrHw_ID_t timerId /* [ IN ] Timer id */ | |
456 | ) { | |
457 | if (pTmrHw[timerId].InterruptStatus) { | |
458 | return tmrHw_INTERRUPT_STATUS_SET; | |
459 | } else { | |
460 | return tmrHw_INTERRUPT_STATUS_UNSET; | |
461 | } | |
462 | } | |
463 | ||
464 | /****************************************************************************/ | |
465 | /** | |
466 | * @brief Indentifies a timer causing interrupt | |
467 | * | |
468 | * This functions returns a timer causing interrupt | |
469 | * | |
470 | * @return 0xFFFFFFFF : No timer causing an interrupt | |
471 | * ! 0xFFFFFFFF : timer causing an interrupt | |
472 | * @note | |
473 | * tmrHw_clearIntrrupt() must be called with a valid timer id after calling this function | |
474 | */ | |
475 | /****************************************************************************/ | |
476 | tmrHw_ID_t tmrHw_getInterruptSource(void /* void */ | |
477 | ) { | |
478 | int i; | |
479 | ||
480 | for (i = 0; i < tmrHw_TIMER_NUM_COUNT; i++) { | |
481 | if (pTmrHw[i].InterruptStatus) { | |
482 | return i; | |
483 | } | |
484 | } | |
485 | ||
486 | return 0xFFFFFFFF; | |
487 | } | |
488 | ||
489 | /****************************************************************************/ | |
490 | /** | |
491 | * @brief Displays specific timer registers | |
492 | * | |
493 | * | |
494 | * @return void | |
495 | * | |
496 | */ | |
497 | /****************************************************************************/ | |
498 | void tmrHw_printDebugInfo(tmrHw_ID_t timerId, /* [ IN ] Timer id */ | |
499 | int (*fpPrint) (const char *, ...) /* [ IN ] Print callback function */ | |
500 | ) { | |
501 | (*fpPrint) ("Displaying register contents \n\n"); | |
502 | (*fpPrint) ("Timer %d: Load value 0x%X\n", timerId, | |
503 | pTmrHw[timerId].LoadValue); | |
504 | (*fpPrint) ("Timer %d: Background load value 0x%X\n", timerId, | |
505 | pTmrHw[timerId].BackgroundLoad); | |
506 | (*fpPrint) ("Timer %d: Control 0x%X\n", timerId, | |
507 | pTmrHw[timerId].Control); | |
508 | (*fpPrint) ("Timer %d: Interrupt clear 0x%X\n", timerId, | |
509 | pTmrHw[timerId].InterruptClear); | |
510 | (*fpPrint) ("Timer %d: Interrupt raw interrupt 0x%X\n", timerId, | |
511 | pTmrHw[timerId].RawInterruptStatus); | |
512 | (*fpPrint) ("Timer %d: Interrupt status 0x%X\n", timerId, | |
513 | pTmrHw[timerId].InterruptStatus); | |
514 | } | |
515 | ||
516 | /****************************************************************************/ | |
517 | /** | |
518 | * @brief Use a timer to perform a busy wait delay for a number of usecs. | |
519 | * | |
520 | * @return N/A | |
521 | */ | |
522 | /****************************************************************************/ | |
523 | void tmrHw_udelay(tmrHw_ID_t timerId, /* [ IN ] Timer id */ | |
524 | unsigned long usecs /* [ IN ] usec to delay */ | |
525 | ) { | |
526 | tmrHw_RATE_t usec_tick_rate; | |
527 | tmrHw_COUNT_t start_time; | |
528 | tmrHw_COUNT_t delta_time; | |
529 | ||
530 | start_time = tmrHw_GetCurrentCount(timerId); | |
531 | usec_tick_rate = tmrHw_divide(tmrHw_getCountRate(timerId), 1000000); | |
532 | delta_time = usecs * usec_tick_rate; | |
533 | ||
534 | /* Busy wait */ | |
535 | while (delta_time > (tmrHw_GetCurrentCount(timerId) - start_time)) | |
536 | ; | |
537 | } | |
538 | ||
539 | /****************************************************************************/ | |
540 | /** | |
541 | * @brief Local Divide function | |
542 | * | |
543 | * This function does the divide | |
544 | * | |
545 | * @return divide value | |
546 | * | |
547 | */ | |
548 | /****************************************************************************/ | |
549 | static int tmrHw_divide(int num, int denom) | |
550 | { | |
551 | int r; | |
552 | int t = 1; | |
553 | ||
554 | /* Shift denom and t up to the largest value to optimize algorithm */ | |
555 | /* t contains the units of each divide */ | |
556 | while ((denom & 0x40000000) == 0) { /* fails if denom=0 */ | |
557 | denom = denom << 1; | |
558 | t = t << 1; | |
559 | } | |
560 | ||
b595076a | 561 | /* Initialize the result */ |
7ba09020 LC |
562 | r = 0; |
563 | ||
564 | do { | |
565 | /* Determine if there exists a positive remainder */ | |
566 | if ((num - denom) >= 0) { | |
567 | /* Accumlate t to the result and calculate a new remainder */ | |
568 | num = num - denom; | |
569 | r = r + t; | |
570 | } | |
571 | /* Continue to shift denom and shift t down to 0 */ | |
572 | denom = denom >> 1; | |
573 | t = t >> 1; | |
574 | } while (t != 0); | |
575 | return r; | |
576 | } |