Pileus Git - ~andy/csm213a-hw/blob - hw2/main.cpp

   1 #include "messages.h"
   2
   3 #include "mbed.h"
   4 #include "serial_irq.h"
   5 #include "serial_dma.h"
   6 #include "timer_dma.h"
   7
   8 /**
   9  * Mode of operation:
  10  *   Devices 1 and 2 synchronize clocks using serial messages.
  11  *
  12  *   1. Each serial message timestamped using the hardware timer capture
  13  *      registers in both the sender and receiver.
  14  *   2. The sender transmits the send timestamp during the next time-sync
  15  *      message.
  16  *   3. The receiver then compares the senders timestamp with it's own
  17  *      timestamp for the corresponding messages and calculates an offset.
  18  *   4. The offset is used to compensate the receivers local clock.
  19  *
  20  *   Time synchronization is performed in both directions.
  21  */
  22
  23 /*******************
  24  * Timer functions *
  25  *******************/
  26
  27 #define NSEC_PER_SEC 1000000000ULL
  28
  29 uint64_t time_last_local; // timestamp at last time sync
  30 uint64_t time_last_world; // offset at last time sync
  31
  32 /**
  33  * Generate time stamp for an async event:
  34  *   local: drift compensated wall-clock time
  35  *   world: nanoseconds in world time world
  36  *   valid: local timestamp at valid valid
  37  */
  38 //uint64_t time_to_local(uint64_t world, uint64_t valid)
  39 //{
  40 //      uint64_t now =
  41 //      local =  + (stamp);
  42 //}
  43
  44 /**
  45  * Generate time stamp for an async event:
  46  *   time:  drift compensated wall-clock time
  47  *   stamp: event timestamp from PIT Module
  48  */
  49 uint64_t time_to_world(uint64_t local)
  50 {
  51         uint64_t elapsed = local - time_last_local;
  52         return time_last_world + elapsed;
  53 }
  54
  55 /**
  56  * Compensate the Real-Time-Clock oscillator for
  57  * temperature and drift errors. Called at 1Hz and
  58  * synchronous to the RTC 1Hz output.
  59  */
  60 void time_rtc_comp(void)
  61 {
  62         // todo
  63 }
  64
  65 /**
  66  * Synchronize the timer internal state with updates
  67  * from an external time sync message.
  68  *   local: our internal timestamp for the event
  69  *   world: reference timestamp from the other device
  70  */
  71 void time_ext_init(uint64_t local, uint64_t world)
  72 {
  73         sirq_printf("initialize clocks: %d -> %d\r\n",
  74                         (int)(local/NSEC_PER_SEC),
  75                         (int)(world/NSEC_PER_SEC));
  76
  77         time_last_local = local;
  78         time_last_world = world;
  79 }
  80
  81 /**
  82  * Synchronize the timer internal state with updates
  83  * from an external time sync message.
  84  *   local: our internal timestamp for the event
  85  *   world: reference timestamp from the other device
  86  */
  87 void time_ext_sync(uint64_t local, uint64_t world)
  88 {
  89         uint64_t guess = time_to_world(local);
  90
  91         time_last_local = local;
  92         time_last_world = (guess/2) + (world/2);
  93         //time_last_world = (guess * 3 / 4) + (world * 1 / 4);
  94         //time_last_world =
  95         //      (guess - (        guess / 2)) +
  96         //      (world - (world - world / 2));
  97         //time_last_world =
  98         //      (guess - (guess - guess / 4)) +
  99         //      (world - (        world / 4));
 100
 101         world = time_last_world;
 102
 103 //#ifdef VERBOSE
 104 #if 0
 105         uint64_t error = world > guess ? world - guess :
 106                          guess > world ? guess - world : 0;
 107         int      ahead = guess > world;
 108         sirq_printf("syncing clocks: %6d=%d.%04u -> %d.%04u (err: %s%ld.%09lu)\r\n",
 109                         (int)((local / NSEC_PER_SEC)),
 110                         (int)((guess / NSEC_PER_SEC)),
 111                         (int)((guess % NSEC_PER_SEC)/(NSEC_PER_SEC/10000)),
 112                         (int)((world / NSEC_PER_SEC)),
 113                         (int)((world % NSEC_PER_SEC)/(NSEC_PER_SEC/10000)),
 114                         ahead ? "-" : " ",
 115                         (int32_t )(error / (int64_t)NSEC_PER_SEC),
 116                         (uint32_t)(error % (int64_t)NSEC_PER_SEC));
 117 #endif
 118 //#endif
 119 }
 120
 121 void time_printf(const char *label, uint64_t local)
 122 {
 123         uint64_t world = time_to_world(local);
 124         sirq_printf("%s -- %d.%09u -> %d.%09u\r\n",
 125                         label,
 126                         (int)(local / NSEC_PER_SEC),
 127                         (int)(local % NSEC_PER_SEC),
 128                         (int)(world / NSEC_PER_SEC),
 129                         (int)(world % NSEC_PER_SEC));
 130 }
 131
 132 /*********************
 133  * Signal generation *
 134  *********************/
 135
 136 static uint32_t *emit_pcr    = 0; // transmit pin name
 137
 138 static uint64_t  emit_start  = 0; // transmit start time (world time)
 139 static uint64_t  emit_period = 0; // transmit period
 140 static uint64_t  emit_due    = 0; // next transmit (world time)
 141
 142 static uint32_t  emit_slack  = 0; // how far ahead we need to schedule, in us
 143 static uint32_t  emit_worst  = 0; // worst-case latency in task table
 144
 145 void emit_init(int alt, PinName pin, PinMode mode)
 146 {
 147         // Find pin
 148         emit_pcr = (uint32_t*)(PORTA_BASE + pin);
 149
 150         // Enable clocks
 151         SIM->SCGC6            |= SIM_SCGC6_TPM0_MASK;
 152
 153         SIM->SOPT2            |= SIM_SOPT2_TPMSRC(1);
 154         SIM->SOPT4            |= SIM_SOPT4_TPM1CLKSEL_MASK;
 155
 156         // Set pin mode
 157         emit_pcr[0]            = PORT_PCR_ISF_MASK
 158                                | PORT_PCR_MUX(alt)
 159                                | mode;
 160
 161         // Setup Timer/PWM Module
 162         TPM0->SC               = TPM_SC_TOF_MASK
 163                                | TPM_SC_PS(1);        // 24 MHz clock ?
 164         TPM0->CNT              = TPM_CNT_COUNT(0);
 165         TPM0->MOD              = TPM_MOD_MOD(0xFFFF);
 166
 167         TPM0->CONTROLS[0].CnSC = TPM_CnSC_CHF_MASK    // clear flag
 168                                | TPM_CnSC_MSB_MASK    // pulse output on match
 169                                | TPM_CnSC_MSA_MASK    // ..
 170                                | TPM_CnSC_ELSA_MASK;  // pulse high
 171
 172         TPM0->CONTROLS[0].CnV  = 0xFFFF;              // time delay
 173
 174         TPM0->STATUS           = TPM_STATUS_CH0F_MASK
 175                                | TPM_STATUS_TOF_MASK;
 176
 177         TPM0->CONF             = TPM_CONF_CSOO_MASK;
 178 }
 179
 180 void emit_enable(uint64_t start, uint64_t period)
 181 {
 182         const int slack_tick = 0xC000; // tune based on emit_worst
 183
 184         emit_start  = start;
 185         emit_period = period;
 186         emit_due    = start + period;
 187
 188         emit_slack  = slack_tick * 1000 / 24;
 189
 190         time_printf("emit scheduled", emit_due);
 191 }
 192
 193 void emit_schedule(uint64_t when)
 194 {
 195         uint64_t now   = time_to_world(tdma_time());
 196         uint16_t delay = (uint16_t)(when-now);
 197
 198         // Clear pending flags
 199         //emit_pcr[0]           |= PORT_PCR_ISF_MASK
 200
 201         // Disable timer
 202         TPM0->SC               = TPM_SC_TOF_MASK;
 203
 204         // Set transmit time
 205         TPM0->CNT              = TPM_CNT_COUNT(0);
 206         TPM0->CONTROLS[0].CnV  = delay;
 207
 208         // Start the timer
 209         TPM0->SC               = TPM_SC_TOF_MASK
 210                                | TPM_SC_CMOD(1);
 211
 212         // Debug
 213         sirq_printf("emitting event\r\n");
 214 }
 215
 216 void emit_transmit(uint64_t local, uint64_t world)
 217 {
 218         static uint64_t prev = 0;
 219
 220         // Record how how much time we have to reschedule
 221         if (prev && (local-prev) > emit_worst)
 222                 emit_worst = (local-prev);
 223         prev = local;
 224
 225         // Schedule task if needed
 226         if (emit_due && emit_period &&
 227             world+emit_slack > emit_due) {
 228                 emit_schedule(emit_due);
 229                 emit_due += emit_period;
 230         }
 231 }
 232
 233 /************************
 234  * Serial I/O functions *
 235  ************************/
 236
 237 typedef struct {
 238         int      index;
 239         int      state;
 240         uint8_t  buffer[256];
 241 } parser_t;
 242
 243 static uint32_t serial_device_id   = 0;
 244
 245 const  uint64_t serial_sync_delay  = NSEC_PER_SEC / 100; // 1hz
 246 static uint64_t serial_sync_due    = 0;
 247
 248 static tdma_t  *serial_tdma_rcv    = NULL;
 249 static tdma_t  *serial_tdma_xmt    = NULL;
 250
 251 static uint64_t serial_prev_local  = 0;
 252 static uint64_t serial_prev_seq    = 0;
 253
 254 static uint64_t serial_xmt_local   = 0;
 255 static uint64_t serial_xmt_seq     = 0;
 256
 257 /**
 258  * Convert world to local time
 259  */
 260 uint64_t serial_read_time(ntime_t time)
 261 {
 262         return ((uint64_t)time.seconds) * NSEC_PER_SEC
 263              + ((uint64_t)time.nanosec);
 264 }
 265
 266 ntime_t serial_write_time(uint64_t time)
 267 {
 268         ntime_t buf = {};
 269         buf.seconds = time / NSEC_PER_SEC;
 270         buf.nanosec = time % NSEC_PER_SEC;
 271         return buf;
 272 }
 273
 274 /**
 275  * Output initialization message init message
 276  */
 277 void serial_send_init(uint16_t device, uint64_t local)
 278 {
 279 }
 280
 281 /**
 282  * Output time sync message
 283  */
 284 void serial_send_sync(sirq_t *port, uint64_t now)
 285 {
 286         if (serial_sync_due == 0 || now < serial_sync_due)
 287                 return; // not ready
 288
 289         //sirq_printf("sending sync\r\n");
 290
 291         // Calculate world time
 292         uint64_t local = 0;
 293         uint64_t world = time_to_world(serial_xmt_local);
 294
 295         // Message data
 296         header_t   head;
 297         sync_msg_t body;
 298
 299         // Transmit sync message
 300         head.header = MSG_HEADER;
 301         head.msgid  = MSG_ID_SYNC;
 302         head.length = sizeof(body);
 303         head.cksum  = 0; // todo
 304
 305         body.seq          = serial_xmt_seq;
 306         body.time.seconds = world / NSEC_PER_SEC;
 307         body.time.nanosec = world % NSEC_PER_SEC;
 308
 309         tdma_stop(serial_tdma_rcv);
 310
 311         tdma_start(serial_tdma_xmt);
 312         sirq_write(port, &head, sizeof(head));
 313         sirq_write(port, &body, sizeof(body));
 314         tdma_stop(serial_tdma_xmt);
 315
 316         // save transmit time
 317         int valid = tdma_stamp(serial_tdma_xmt, &local);
 318         if (!valid)
 319                 sirq_printf("sync transmit time -- missed\r\n");
 320         else
 321                 //time_printf("sync transmit time ", local);
 322
 323         tdma_start(serial_tdma_rcv);
 324
 325         serial_xmt_seq  += 1;
 326         serial_sync_due  = 0;
 327         serial_xmt_local = local;
 328 }
 329
 330 /**
 331  * Output external event received message
 332  *   event: id of the received event
 333  *   time:  compensated timestamp of the event
 334  */
 335 void serial_send_event(uint16_t event, uint64_t local)
 336 {
 337         time_printf("event received", local);
 338
 339 #if 0
 340         // Message data
 341         header_t    head;
 342         event_msg_t body;
 343
 344         uint64_t world = time_to_world(local);
 345
 346         ntime_t time = {};
 347         time.seconds = (uint32_t)(world / NSEC_PER_SEC);
 348         time.nanosec = (uint32_t)(world % NSEC_PER_SEC);
 349
 350         // Transmit sync message
 351         head.header = MSG_HEADER;
 352         head.msgid  = MSG_ID_SYNC;
 353         head.length = sizeof(body);
 354         head.cksum  = 0; // todo
 355
 356         body.seq          = serial_xmt_seq;
 357         body.time.seconds = world / NSEC_PER_SEC;
 358         body.time.nanosec = world % NSEC_PER_SEC;
 359
 360         tdma_stop(serial_tdma_rcv);
 361
 362         tdma_start(serial_tdma_xmt);
 363         sirq_write(port, &head, sizeof(head));
 364         sirq_write(port, &body, sizeof(body));
 365         tdma_stop(serial_tdma_xmt);
 366 #endif
 367 }
 368
 369 /**
 370  * Handle init message
 371  */
 372 void serial_handle_init(init_msg_t *msg)
 373 {
 374         sirq_printf("initialize: %s %s %s %s %s\r\n",
 375                 msg->valid & MSG_VALID_DEVICE ? "DEV"    : "dev",
 376                 msg->valid & MSG_VALID_START  ? "START"  : "start",
 377                 msg->valid & MSG_VALID_PERIOD ? "PERIOD" : "period",
 378                 msg->valid & MSG_VALID_WORLD  ? "WORLD"  : "world",
 379                 msg->valid & MSG_VALID_SYNC   ? "SYNC"   : "sync");
 380         sirq_printf("  dev    -- %d\r\n", msg->device);
 381         time_printf("  start ", serial_read_time(msg->start));
 382         time_printf("  period", serial_read_time(msg->period));
 383         time_printf("  world ", serial_read_time(msg->world));
 384
 385         if (msg->valid & MSG_VALID_DEVICE)
 386                 serial_device_id = msg->device;
 387
 388         if (msg->valid & MSG_VALID_START ||
 389             msg->valid & MSG_VALID_PERIOD) {
 390                 uint64_t start  = serial_read_time(msg->start);
 391                 uint64_t period = serial_read_time(msg->period);
 392                 emit_enable(start, period);
 393         }
 394
 395         if (msg->valid & MSG_VALID_WORLD) {
 396                 uint64_t world = serial_read_time(msg->world);
 397                 uint64_t local = tdma_time();
 398                 time_ext_init(local, world);
 399         }
 400
 401         if (msg->valid & MSG_VALID_SYNC)
 402                 serial_sync_due = tdma_time() + serial_sync_delay;
 403 }
 404
 405 /**
 406  * Handle sync message
 407  */
 408 void serial_handle_sync(sync_msg_t *msg)
 409 {
 410         // Read receive timestamp for next time sync message
 411         uint64_t current = 0;
 412         int valid = tdma_stamp(serial_tdma_rcv, &current);
 413         if (!valid)
 414                 sirq_printf("sync receive time  -- missing\r\n");
 415         //else
 416         //      time_printf("sync receive time ", current);
 417         tdma_stop(serial_tdma_rcv);
 418
 419         // Lookup times
 420         uint64_t world = ((uint64_t)msg->time.seconds) * NSEC_PER_SEC
 421                        + ((uint64_t)msg->time.nanosec);
 422
 423         // Valid times timestamp
 424         if (serial_prev_seq == (msg->seq-1)) {
 425                 uint64_t local = serial_prev_local;
 426                 time_ext_sync(local, world);
 427         }
 428
 429         // Queue transmit to other board
 430         serial_sync_due   = tdma_time() + serial_sync_delay;
 431
 432         // Update states
 433         serial_prev_local = current;
 434         serial_prev_seq   = msg->seq;
 435 }
 436
 437 /**
 438  * Handle event message
 439  */
 440 void serial_handle_event(event_msg_t *msg)
 441 {
 442 }
 443
 444 /**
 445  * Deliver message
 446  */
 447 void serial_deliver(int msgid, void *body)
 448 {
 449         switch (msgid) {
 450                 case MSG_ID_INIT:
 451                         //sirq_printf("received init msg\r\n");
 452                         serial_handle_init((init_msg_t*)body);
 453                         break;
 454                 case MSG_ID_SYNC:
 455                         //sirq_printf("received sync msg\r\n");
 456                         serial_handle_sync((sync_msg_t*)body);
 457                         break;
 458                 case MSG_ID_EVENT:
 459                         //sirq_printf("received event msg\r\n");
 460                         serial_handle_event((event_msg_t*)body);
 461                         break;
 462         }
 463 }
 464
 465 /**
 466  * Process serial receive messages
 467  */
 468 void serial_receive(parser_t *parser, int byte)
 469 {
 470         //sirq_printf("serial_receive - %02x\r\n", byte);
 471
 472         // Lookup pointers
 473         header_t *head = (header_t*)parser->buffer;
 474         void     *body = (void*)(head+1);
 475         const int max_length = sizeof(parser->buffer)-sizeof(header_t);
 476
 477         // Process uart messages
 478         parser->buffer[parser->index++] = byte;
 479         switch (parser->state) {
 480                 case 0: // Search
 481                         if (parser->index == sizeof(uint16_t)) {
 482                                 if (head->header == MSG_HEADER) {
 483                                         parser->state = 1;
 484                                 } else {
 485                                         parser->buffer[0] = parser->buffer[1];
 486                                         parser->index = 1;
 487                                 }
 488                         }
 489                         break;
 490                 case 1: // Header
 491                         if (parser->index == sizeof(header_t)) {
 492                                 if (head->length <= max_length &&
 493                                     head->msgid  <= MSG_MAX_ID) {
 494                                         parser->state = 2;
 495                                 } else {
 496                                         parser->index = 0;
 497                                         parser->state = 0;
 498                                 }
 499                         }
 500                         break;
 501                 case 2: // Data
 502                         if (parser->index == (int)sizeof(header_t)+head->length) {
 503                                 serial_deliver(head->msgid, body);
 504                                 parser->index = 0;
 505                                 parser->state = 0;
 506                         }
 507                         break;
 508         }
 509 }
 510
 511 /********************
 512  * Data definitions *
 513  ********************/
 514
 515 // LEDs
 516 DigitalOut led1(LED1);
 517 DigitalOut led2(LED2);
 518
 519 // Message Parsers
 520 parser_t   parser_dbg;
 521 parser_t   parser_bbb;
 522 parser_t   parser_mbed;
 523
 524 // Serial IRQ
 525 sirq_t    *sirq_dbg;
 526 sirq_t    *sirq_bbb;
 527 sirq_t    *sirq_mbed;
 528
 529 // Timer DMA
 530 tdma_t    *tdma_evt;
 531 tdma_t    *tdma_rcv;
 532 tdma_t    *tdma_xmt;
 533
 534 /*********
 535  * Tasks *
 536  *********/
 537
 538 void task_serial(uint64_t local, uint64_t world)
 539 {
 540         while (sirq_ready(sirq_dbg)) {
 541                 //sirq_printf("serial recv - dbg\r\n");
 542                 serial_receive(&parser_dbg,  sirq_getc(sirq_dbg));
 543         }
 544
 545         while (sirq_ready(sirq_bbb)) {
 546                 //sirq_printf("serial recv - bbb\r\n");
 547                 serial_receive(&parser_bbb,  sirq_getc(sirq_bbb));
 548         }
 549
 550         while (sirq_ready(sirq_mbed)) {
 551                 //sirq_printf("serial recv - mbed\r\n");
 552                 serial_receive(&parser_mbed, sirq_getc(sirq_mbed));
 553         }
 554 }
 555
 556 void task_events(uint64_t local, uint64_t world)
 557 {
 558         uint64_t event = 0;
 559
 560 #ifdef VERBOSE
 561         if (tdma_stamp(tdma_evt, &event)) {
 562                 sirq_printf("event received - evt\r\n");
 563         if (tdma_stamp(tdma_rcv, &event))
 564                 sirq_printf("event received - rcv\r\n");
 565         if (tdma_stamp(tdma_xmt, &event))
 566                 sirq_printf("event received - xmt\r\n");
 567 #endif
 568
 569         if (tdma_stamp(tdma_evt, &event))
 570                 serial_send_event(0, event);
 571         tdma_stop(tdma_evt);
 572         tdma_start(tdma_evt);
 573 }
 574
 575 void task_sync(uint64_t local, uint64_t world)
 576 {
 577         serial_send_sync(sirq_mbed, local);
 578 }
 579
 580 void task_leds(uint64_t local, uint64_t world)
 581 {
 582         static uint32_t which = 0;
 583         led1 = (which == 0);
 584         led2 = (which == 1);
 585         which ^= 1;
 586 }
 587
 588 void task_emit(uint64_t local, uint64_t world)
 589 {
 590         emit_transmit(local, world);
 591 }
 592
 593 void task_debug(uint64_t local, uint64_t world)
 594 {
 595         //tdma_debug(tdma_rcv);
 596         //tdma_debug(tdma_xmt);
 597
 598         //sirq_debug(sirq_mbed);
 599
 600 #ifdef VERBOSE
 601         sirq_printf("background - %6u.%02u -> %u.%02u\r\n",
 602                         (uint32_t)(local / NSEC_PER_SEC),
 603                         (uint32_t)(local % NSEC_PER_SEC / 10000000),
 604                         (uint32_t)(world / NSEC_PER_SEC),
 605                         (uint32_t)(world % NSEC_PER_SEC / 10000000));
 606 #endif
 607 }
 608
 609 /********
 610  * Main *
 611  ********/
 612
 613 #define N_ELEM(x) (sizeof(x) / sizeof((x)[0]))
 614
 615 extern void test_main(void);
 616 extern serial_t stdio_uart;
 617
 618 static struct {
 619         void (*task)(uint64_t, uint64_t);
 620         uint64_t period;
 621         uint64_t due;
 622 } tasks[] = {
 623         { task_serial, 0          }, // always
 624         { task_events, 0          }, // always -- testing
 625         { task_sync,   0          }, // always
 626         { task_emit,   0          }, // always
 627         { task_leds,   100000000  }, // 10hz
 628         { task_debug,  1000000000 }, // 1hz
 629 };
 630
 631 void background(void)
 632 {
 633         // Debugging
 634         uint64_t local = tdma_time();
 635         uint64_t world = time_to_world(local);
 636
 637         // Run the scheduler
 638         for (unsigned i = 0; i < N_ELEM(tasks); i++) {
 639                 if (local >= tasks[i].due) {
 640                         tasks[i].task(local, world);
 641                         tasks[i].due += tasks[i].period;
 642                 }
 643         }
 644 }
 645
 646 int main(int argc, char **argv)
 647 {
 648         tdma_init();
 649         emit_init(4, PTC1, PullDown);
 650
 651         // Open serial ports
 652         sirq_dbg   = sirq_open(SIRQ_UART0, USBTX, USBRX, 115200); // to pc
 653         sirq_bbb   = sirq_open(SIRQ_UART1, PTE0,  PTE1,  115200); // to bbb
 654         sirq_mbed  = sirq_open(SIRQ_UART2, PTD3,  PTD2,  115200); // to mbed
 655
 656         // Setup timers
 657         tdma_evt   = tdma_open(TDMA_CHAN0, 3, PTC9,  PullDown); // async event
 658
 659         // mbed time sync
 660         tdma_rcv   = tdma_open(TDMA_CHAN2, 3, PTD2,  PullUp);   // time sync rcv
 661         tdma_xmt   = tdma_open(TDMA_CHAN3, 3, PTD3,  PullUp);   // time sync xmt
 662
 663         // host time sync
 664         //tdma_rcv   = tdma_open(TDMA_CHAN2, 2, USBRX, PullUp); // time sync rcv
 665         //tdma_xmt   = tdma_open(TDMA_CHAN3, 2, USBTX, PullUp); // time sync xmt
 666
 667         // start timers
 668         tdma_start(tdma_evt);
 669         tdma_start(tdma_rcv);
 670         tdma_start(tdma_xmt);
 671
 672         // Serial timestamping
 673         serial_tdma_rcv = tdma_rcv;
 674         serial_tdma_xmt = tdma_xmt;
 675
 676         // Test clocks
 677         //MCG->C1    = 0x05; // was 0x1A
 678         //MCG->C2    = 0x2C; // was 0x24
 679         //MCG->C3    = 0x91; // was 0x91
 680         //MCG->C4    = 0x10; // was 0x10
 681         //MCG->C5    = 0x01; // was 0x01
 682         //MCG->C6    = 0x40; // was 0x40
 683         //MCG->S     = 0x6E; // was 0x6E
 684         //MCG->SC    = 0x02; // was 0x02
 685         //MCG->ATCVH = 0x00; // was 0x00
 686         //MCG->ATCVL = 0x00; // was 0x00
 687         //MCG->C7    = 0x00; // was 0x00
 688         //MCG->C8    = 0x80; // was 0x80
 689         //MCG->C9    = 0x00; // was 0x00
 690         //MCG->C10   = 0x00; // was 0x00
 691
 692         //sirq_printf("MGC - C1    %02hx\r\n", MCG->C1);     // 1A
 693         //sirq_printf("MGC - C2    %02hx\r\n", MCG->C2);     // 24
 694         //sirq_printf("MGC - C3    %02hx\r\n", MCG->C3);     // 91
 695         //sirq_printf("MGC - C4    %02hx\r\n", MCG->C4);     // 10
 696         //sirq_printf("MGC - C5    %02hx\r\n", MCG->C5);     // 01
 697         //sirq_printf("MGC - C6    %02hx\r\n", MCG->C6);     // 40
 698         //sirq_printf("MGC - S     %02hx\r\n", MCG->S);      // 6E
 699         //sirq_printf("MGC - SC    %02hx\r\n", MCG->SC);     // 02
 700         //sirq_printf("MGC - ATCVH %02hx\r\n", MCG->ATCVH);  // 00
 701         //sirq_printf("MGC - ATCVL %02hx\r\n", MCG->ATCVL);  // 00
 702         //sirq_printf("MGC - C7    %02hx\r\n", MCG->C7);     // 00
 703         //sirq_printf("MGC - C8    %02hx\r\n", MCG->C8);     // 80
 704         //sirq_printf("MGC - C9    %02hx\r\n", MCG->C9);     // 00
 705         //sirq_printf("MGC - C10   %02hx\r\n", MCG->C10);    // 00
 706
 707         // Run background loop
 708         while (true)
 709                 background();
 710
 711         // Performance testing
 712         //uint64_t prev = 0, due = 0;
 713         //uint64_t worst[10] = {};
 714         //int      count = 0;
 715         //while (true) {
 716         //      uint64_t local = tdma_time();
 717         //      if (prev && (local-prev) > worst[count])
 718         //              worst[count] = (local-prev);
 719         //      prev = local;
 720         //      if (local > due) {
 721         //              if (count == 5) {
 722         //                      static char str[] = "background background background\r\n";
 723         //                      sirq_write(sirq_dbg, str, sizeof(str));
 724         //              }
 725         //              if (count == 9) {
 726         //                      sirq_printf("background\r\n");
 727         //                      for (int i = 0; i < 10; i++) {
 728         //                              sirq_printf("  worst[%d] = 0.%09u\r\n",
 729         //                                              i, worst[i]);
 730         //                              worst[i] = 0;
 731         //                      }
 732         //              }
 733         //              due += NSEC_PER_SEC;
 734         //              count = (count + 1) % 10;
 735         //      }
 736         //}
 737
 738         // Run tests
 739         //test_main();
 740
 741         return 0;
 742 }