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  *   time:  drift compensated wall-clock time
  35  *   stamp: event timestamp from PIT Module
  36  */
  37 uint64_t time_to_world(uint64_t local)
  38 {
  39         uint64_t elapsed = local - time_last_local;
  40         return time_last_world + elapsed;
  41 }
  42
  43 /**
  44  * Synchronize the timer internal state with updates
  45  * from an external time sync message.
  46  *   local: our internal timestamp for the event
  47  *   world: reference timestamp from the other device
  48  */
  49 void time_ext_init(uint64_t local, uint64_t world)
  50 {
  51         sirq_printf("initialize clocks: %d -> %d\r\n",
  52                         (int)(local/NSEC_PER_SEC),
  53                         (int)(world/NSEC_PER_SEC));
  54
  55         time_last_local = local;
  56         time_last_world = world;
  57 }
  58
  59 /**
  60  * Synchronize the timer internal state with updates
  61  * from an external time sync message.
  62  *   local: our internal timestamp for the event
  63  *   world: reference timestamp from the other device
  64  */
  65 void time_ext_sync(uint64_t local, uint64_t world)
  66 {
  67         uint64_t guess = time_to_world(local);
  68
  69         time_last_local = local;
  70         time_last_world = (guess/2) + (world/2);
  71         //time_last_world = (guess * 3 / 4) + (world * 1 / 4);
  72         //time_last_world =
  73         //      (guess - (        guess / 2)) +
  74         //      (world - (world - world / 2));
  75         //time_last_world =
  76         //      (guess - (guess - guess / 4)) +
  77         //      (world - (        world / 4));
  78
  79         world = time_last_world;
  80
  81 //#ifdef VERBOSE
  82 #if 1
  83         uint64_t error = world > guess ? world - guess :
  84                          guess > world ? guess - world : 0;
  85         int      ahead = guess > world;
  86         sirq_printf("syncing clocks: %6d=%d.%04u -> %d.%04u (err: %s%ld.%09lu)\r\n",
  87                         (int)((local / NSEC_PER_SEC)),
  88                         (int)((guess / NSEC_PER_SEC)),
  89                         (int)((guess % NSEC_PER_SEC)/(NSEC_PER_SEC/10000)),
  90                         (int)((world / NSEC_PER_SEC)),
  91                         (int)((world % NSEC_PER_SEC)/(NSEC_PER_SEC/10000)),
  92                         ahead ? "-" : " ",
  93                         (int32_t )(error / (int64_t)NSEC_PER_SEC),
  94                         (uint32_t)(error % (int64_t)NSEC_PER_SEC));
  95 #endif
  96 //#endif
  97 }
  98
  99 void time_printf(const char *label, uint64_t local)
 100 {
 101         uint64_t world = time_to_world(local);
 102         sirq_printf("%s -- %d.%09u -> %d.%09u\r\n",
 103                         label,
 104                         (int)(local / NSEC_PER_SEC),
 105                         (int)(local % NSEC_PER_SEC),
 106                         (int)(world / NSEC_PER_SEC),
 107                         (int)(world % NSEC_PER_SEC));
 108 }
 109
 110 /*********************
 111  * Signal generation *
 112  *********************/
 113
 114 #define EMIT_CLOCKS(nsec) ((uint16_t)((nsec) * 24 / 1000))
 115 #define EMIT_NSEC(clocks) ((uint16_t)((clocks) * 1000 / 24))
 116
 117 static uint32_t *emit_pcr    = 0; // transmit pin name
 118
 119 static uint64_t  emit_start  = 0; // transmit start time (world time)
 120 static uint64_t  emit_period = 0; // transmit period
 121 static uint64_t  emit_due    = 0; // next transmit (world time)
 122
 123 static uint32_t  emit_slack  = 0; // how far ahead we need to schedule, in us
 124 static uint32_t  emit_worst  = 0; // worst-case latency in task table
 125
 126 void emit_init(int alt, PinName pin, PinMode mode)
 127 {
 128         // Find pin
 129         emit_pcr = (uint32_t*)(PORTA_BASE + pin);
 130
 131         // Enable clocks
 132         SIM->SCGC6            |= SIM_SCGC6_TPM1_MASK;
 133         SIM->SOPT2            |= SIM_SOPT2_TPMSRC(1);
 134
 135         // Set pin mode
 136         emit_pcr[0]            = PORT_PCR_ISF_MASK
 137                                | PORT_PCR_MUX(alt)
 138                                | mode;
 139
 140         // Setup Timer/PWM Module
 141         TPM1->SC               = TPM_SC_TOF_MASK;
 142         TPM1->CNT              = TPM_CNT_COUNT(0);
 143         TPM1->MOD              = TPM_MOD_MOD(0xFFFF);
 144
 145         TPM1->CONTROLS[0].CnSC = TPM_CnSC_CHF_MASK    // clear flag
 146                                | TPM_CnSC_MSB_MASK    // set output highon match,
 147                                | TPM_CnSC_ELSB_MASK   // cleared on overflow
 148                                | TPM_CnSC_ELSA_MASK;  // ..
 149
 150         TPM1->STATUS           = TPM_STATUS_CH0F_MASK
 151                                | TPM_STATUS_TOF_MASK;
 152
 153         TPM1->CONF             = TPM_CONF_CSOO_MASK;
 154 }
 155
 156 void emit_enable(uint64_t start, uint64_t period)
 157 {
 158         const int slack_clocks = 0x8000; // tune based on emit_worst
 159
 160         emit_start  = start;
 161         emit_period = period;
 162         emit_due    = start + period;
 163
 164         // TODO - tune slack time
 165         // TODO - check clock power
 166         // TODO - TPM clock source
 167         emit_slack  = EMIT_NSEC(slack_clocks);
 168
 169         time_printf("emit scheduled", emit_due);
 170 }
 171
 172 void emit_schedule(uint64_t when)
 173 {
 174         uint64_t now    = time_to_world(tdma_time());
 175         uint64_t start  = when - now;     // transmit time
 176         uint64_t stop   = start + 100000; // 100 us pulse
 177
 178         // Disable timer
 179         TPM1->SC               = TPM_SC_TOF_MASK;
 180
 181         // Set transmit time
 182         TPM1->CONTROLS[0].CnV  = EMIT_CLOCKS(start);
 183         TPM1->MOD              = TPM_MOD_MOD(EMIT_CLOCKS(stop));
 184
 185         // Start the timer
 186         TPM1->SC               = TPM_SC_TOF_MASK
 187                                | TPM_SC_PS(1)
 188                                | TPM_SC_CMOD(1);
 189
 190         // Debug output
 191         //sirq_printf("emitting event\r\n");
 192 }
 193
 194 void emit_transmit(uint64_t local, uint64_t world)
 195 {
 196         static uint64_t prev = 0;
 197
 198         // Record how how much time we have to reschedule
 199         if (prev && (local-prev) > emit_worst)
 200                 emit_worst = (local-prev);
 201         prev = local;
 202
 203         // Schedule task if needed
 204         if (emit_due && emit_period &&
 205             world+emit_slack > emit_due) {
 206                 emit_schedule(emit_due);
 207                 emit_due += emit_period;
 208         }
 209 }
 210
 211 /************************
 212  * Serial I/O functions *
 213  ************************/
 214
 215 typedef struct {
 216         int      index;
 217         int      state;
 218         uint8_t  buffer[256];
 219 } parser_t;
 220
 221 static uint32_t serial_device_id   = 0;
 222
 223 const  uint64_t serial_sync_delay  = NSEC_PER_SEC / 100; // 1hz
 224 static uint64_t serial_sync_due    = 0;
 225
 226 static tdma_t  *serial_tdma_rcv    = NULL;
 227 static tdma_t  *serial_tdma_xmt    = NULL;
 228
 229 static uint64_t serial_prev_local  = 0;
 230 static uint64_t serial_prev_seq    = 0;
 231
 232 static uint64_t serial_xmt_local   = 0;
 233 static uint64_t serial_xmt_seq     = 0;
 234
 235 /**
 236  * Convert world to local time
 237  */
 238 uint64_t serial_read_time(ntime_t time)
 239 {
 240         return ((uint64_t)time.seconds) * NSEC_PER_SEC
 241              + ((uint64_t)time.nanosec);
 242 }
 243
 244 ntime_t serial_write_time(uint64_t time)
 245 {
 246         ntime_t buf = {};
 247         buf.seconds = time / NSEC_PER_SEC;
 248         buf.nanosec = time % NSEC_PER_SEC;
 249         return buf;
 250 }
 251
 252 /**
 253  * Output initialization message init message
 254  */
 255 void serial_send_init(uint16_t device, uint64_t local)
 256 {
 257 }
 258
 259 /**
 260  * Output time sync message
 261  */
 262 void serial_send_sync(sirq_t *port, uint64_t now)
 263 {
 264         if (serial_sync_due == 0 || now < serial_sync_due)
 265                 return; // not ready
 266
 267         //sirq_printf("sending sync\r\n");
 268
 269         // Calculate world time
 270         uint64_t local = 0;
 271         uint64_t world = time_to_world(serial_xmt_local);
 272
 273         // Message data
 274         header_t   head;
 275         sync_msg_t body;
 276
 277         // Transmit sync message
 278         head.header = MSG_HEADER;
 279         head.msgid  = MSG_ID_SYNC;
 280         head.length = sizeof(body);
 281         head.cksum  = 0; // todo
 282
 283         body.seq          = serial_xmt_seq;
 284         body.time.seconds = world / NSEC_PER_SEC;
 285         body.time.nanosec = world % NSEC_PER_SEC;
 286
 287         tdma_stop(serial_tdma_rcv);
 288
 289         tdma_start(serial_tdma_xmt);
 290         sirq_write(port, &head, sizeof(head));
 291         sirq_write(port, &body, sizeof(body));
 292         tdma_stop(serial_tdma_xmt);
 293
 294         // save transmit time
 295         int valid = tdma_stamp(serial_tdma_xmt, &local);
 296         if (!valid)
 297                 sirq_printf("sync transmit time -- missed\r\n");
 298         else
 299                 //time_printf("sync transmit time ", local);
 300
 301         tdma_start(serial_tdma_rcv);
 302
 303         serial_xmt_seq  += 1;
 304         serial_sync_due  = 0;
 305         serial_xmt_local = local;
 306 }
 307
 308 /**
 309  * Output external event received message
 310  *   event: id of the received event
 311  *   time:  compensated timestamp of the event
 312  */
 313 void serial_send_event(sirq_t *port, uint16_t event, uint64_t local)
 314 {
 315         time_printf("event received", local);
 316
 317         // Convert timestamp
 318         uint64_t world = time_to_world(local);
 319         ntime_t  ntime = serial_write_time(world);
 320
 321         // Message data
 322         header_t    head = {};
 323         event_msg_t body = {};
 324
 325         // Transmit sync message
 326         head.header = MSG_HEADER;
 327         head.msgid  = MSG_ID_EVENT;
 328         head.length = sizeof(body);
 329         head.cksum  = 0; // todo
 330
 331         body.device = serial_device_id;
 332         body.event  = event;
 333         body.time   = ntime;
 334
 335         // Transmit message to BBB
 336         sirq_write(port, &head, sizeof(head));
 337         sirq_write(port, &body, sizeof(body));
 338 }
 339
 340 /**
 341  * Handle init message
 342  */
 343 void serial_handle_init(init_msg_t *msg)
 344 {
 345         sirq_printf("initialize: %s %s %s %s %s\r\n",
 346                 msg->valid & MSG_VALID_DEVICE ? "DEV"    : "dev",
 347                 msg->valid & MSG_VALID_START  ? "START"  : "start",
 348                 msg->valid & MSG_VALID_PERIOD ? "PERIOD" : "period",
 349                 msg->valid & MSG_VALID_WORLD  ? "WORLD"  : "world",
 350                 msg->valid & MSG_VALID_SYNC   ? "SYNC"   : "sync");
 351         sirq_printf("  dev    -- %d\r\n", msg->device);
 352         time_printf("  start ", serial_read_time(msg->start));
 353         time_printf("  period", serial_read_time(msg->period));
 354         time_printf("  world ", serial_read_time(msg->world));
 355
 356         if (msg->valid & MSG_VALID_DEVICE)
 357                 serial_device_id = msg->device;
 358
 359         if (msg->valid & MSG_VALID_START ||
 360             msg->valid & MSG_VALID_PERIOD) {
 361                 uint64_t start  = serial_read_time(msg->start);
 362                 uint64_t period = serial_read_time(msg->period);
 363                 emit_enable(start, period);
 364         }
 365
 366         if (msg->valid & MSG_VALID_WORLD) {
 367                 uint64_t world = serial_read_time(msg->world);
 368                 uint64_t local = tdma_time();
 369                 time_ext_init(local, world);
 370         }
 371
 372         if (msg->valid & MSG_VALID_SYNC)
 373                 serial_sync_due = tdma_time() + serial_sync_delay;
 374 }
 375
 376 /**
 377  * Handle sync message
 378  */
 379 void serial_handle_sync(sync_msg_t *msg)
 380 {
 381         // Read receive timestamp for next time sync message
 382         uint64_t current = 0;
 383         int valid = tdma_stamp(serial_tdma_rcv, &current);
 384         if (!valid)
 385                 sirq_printf("sync receive time  -- missing\r\n");
 386         //else
 387         //      time_printf("sync receive time ", current);
 388         tdma_stop(serial_tdma_rcv);
 389
 390         // Lookup times
 391         uint64_t world = ((uint64_t)msg->time.seconds) * NSEC_PER_SEC
 392                        + ((uint64_t)msg->time.nanosec);
 393
 394         // Valid times timestamp
 395         if (serial_prev_seq == (msg->seq-1)) {
 396                 uint64_t local = serial_prev_local;
 397                 time_ext_sync(local, world);
 398         }
 399
 400         // Queue transmit to other board
 401         serial_sync_due   = tdma_time() + serial_sync_delay;
 402
 403         // Update states
 404         serial_prev_local = current;
 405         serial_prev_seq   = msg->seq;
 406 }
 407
 408 /**
 409  * Handle event message
 410  */
 411 void serial_handle_event(event_msg_t *msg)
 412 {
 413 }
 414
 415 /**
 416  * Deliver message
 417  */
 418 void serial_deliver(int msgid, void *body)
 419 {
 420         switch (msgid) {
 421                 case MSG_ID_INIT:
 422                         //sirq_printf("received init msg\r\n");
 423                         serial_handle_init((init_msg_t*)body);
 424                         break;
 425                 case MSG_ID_SYNC:
 426                         //sirq_printf("received sync msg\r\n");
 427                         serial_handle_sync((sync_msg_t*)body);
 428                         break;
 429                 case MSG_ID_EVENT:
 430                         //sirq_printf("received event msg\r\n");
 431                         serial_handle_event((event_msg_t*)body);
 432                         break;
 433         }
 434 }
 435
 436 /**
 437  * Process serial receive messages
 438  */
 439 void serial_receive(parser_t *parser, int byte)
 440 {
 441         //sirq_printf("serial_receive - %02x\r\n", byte);
 442
 443         // Lookup pointers
 444         header_t *head = (header_t*)parser->buffer;
 445         void     *body = (void*)(head+1);
 446         const int max_length = sizeof(parser->buffer)-sizeof(header_t);
 447
 448         // Process uart messages
 449         parser->buffer[parser->index++] = byte;
 450         switch (parser->state) {
 451                 case 0: // Search
 452                         if (parser->index == sizeof(uint16_t)) {
 453                                 if (head->header == MSG_HEADER) {
 454                                         parser->state = 1;
 455                                 } else {
 456                                         parser->buffer[0] = parser->buffer[1];
 457                                         parser->index = 1;
 458                                 }
 459                         }
 460                         break;
 461                 case 1: // Header
 462                         if (parser->index == sizeof(header_t)) {
 463                                 if (head->length <= max_length &&
 464                                     head->msgid  <= MSG_MAX_ID) {
 465                                         parser->state = 2;
 466                                 } else {
 467                                         parser->index = 0;
 468                                         parser->state = 0;
 469                                 }
 470                         }
 471                         break;
 472                 case 2: // Data
 473                         if (parser->index == (int)sizeof(header_t)+head->length) {
 474                                 serial_deliver(head->msgid, body);
 475                                 parser->index = 0;
 476                                 parser->state = 0;
 477                         }
 478                         break;
 479         }
 480 }
 481
 482 /********************
 483  * Data definitions *
 484  ********************/
 485
 486 // LEDs
 487 DigitalOut led1(LED1);
 488 DigitalOut led2(LED2);
 489
 490 // Message Parsers
 491 parser_t   parser_dbg;
 492 parser_t   parser_bbb;
 493 parser_t   parser_mbed;
 494
 495 // Serial IRQ
 496 sirq_t    *sirq_dbg;
 497 sirq_t    *sirq_bbb;
 498 sirq_t    *sirq_mbed;
 499
 500 // Timer DMA
 501 tdma_t    *tdma_evt;
 502 tdma_t    *tdma_rcv;
 503 tdma_t    *tdma_xmt;
 504
 505 /*********
 506  * Tasks *
 507  *********/
 508
 509 void task_serial(uint64_t local, uint64_t world)
 510 {
 511         while (sirq_ready(sirq_dbg)) {
 512                 //sirq_printf("serial recv - dbg\r\n");
 513                 serial_receive(&parser_dbg,  sirq_getc(sirq_dbg));
 514         }
 515
 516         while (sirq_ready(sirq_bbb)) {
 517                 //sirq_printf("serial recv - bbb\r\n");
 518                 serial_receive(&parser_bbb,  sirq_getc(sirq_bbb));
 519         }
 520
 521         while (sirq_ready(sirq_mbed)) {
 522                 //sirq_printf("serial recv - mbed\r\n");
 523                 serial_receive(&parser_mbed, sirq_getc(sirq_mbed));
 524         }
 525 }
 526
 527 void task_events(uint64_t local, uint64_t world)
 528 {
 529         uint64_t event = 0;
 530
 531 #ifdef VERBOSE
 532         if (tdma_stamp(tdma_evt, &event)) {
 533                 sirq_printf("event received - evt\r\n");
 534         if (tdma_stamp(tdma_rcv, &event))
 535                 sirq_printf("event received - rcv\r\n");
 536         if (tdma_stamp(tdma_xmt, &event))
 537                 sirq_printf("event received - xmt\r\n");
 538 #endif
 539
 540         if (tdma_stamp(tdma_evt, &event))
 541                 serial_send_event(sirq_bbb, 0, event);
 542         tdma_stop(tdma_evt);
 543         tdma_start(tdma_evt);
 544 }
 545
 546 void task_sync(uint64_t local, uint64_t world)
 547 {
 548         serial_send_sync(sirq_mbed, local);
 549 }
 550
 551 void task_leds(uint64_t local, uint64_t world)
 552 {
 553         static uint32_t which = 0;
 554         led1 = (which == 0);
 555         led2 = (which == 1);
 556         which ^= 1;
 557 }
 558
 559 void task_emit(uint64_t local, uint64_t world)
 560 {
 561         emit_transmit(local, world);
 562 }
 563
 564 void task_debug(uint64_t local, uint64_t world)
 565 {
 566         //tdma_debug(tdma_rcv);
 567         //tdma_debug(tdma_xmt);
 568
 569         //sirq_debug(sirq_mbed);
 570
 571 #ifdef VERBOSE
 572         sirq_printf("background - %6u.%02u -> %u.%02u\r\n",
 573                         (uint32_t)(local / NSEC_PER_SEC),
 574                         (uint32_t)(local % NSEC_PER_SEC / 10000000),
 575                         (uint32_t)(world / NSEC_PER_SEC),
 576                         (uint32_t)(world % NSEC_PER_SEC / 10000000));
 577 #endif
 578 }
 579
 580 /********
 581  * Main *
 582  ********/
 583
 584 #define N_ELEM(x) (sizeof(x) / sizeof((x)[0]))
 585
 586 extern void test_main(void);
 587 extern serial_t stdio_uart;
 588
 589 static struct {
 590         void (*task)(uint64_t, uint64_t);
 591         uint64_t period;
 592         uint64_t due;
 593 } tasks[] = {
 594         { task_serial, 0          }, // always
 595         { task_events, 0          }, // always -- testing
 596         { task_sync,   0          }, // always
 597         { task_emit,   0          }, // always
 598         { task_leds,   100000000  }, // 10hz
 599         { task_debug,  1000000000 }, // 1hz
 600 };
 601
 602 void background(void)
 603 {
 604         // Debugging
 605         uint64_t local = tdma_time();
 606         uint64_t world = time_to_world(local);
 607
 608         // Run the scheduler
 609         for (unsigned i = 0; i < N_ELEM(tasks); i++) {
 610                 if (local >= tasks[i].due) {
 611                         tasks[i].task(local, world);
 612                         tasks[i].due += tasks[i].period;
 613                 }
 614         }
 615 }
 616
 617 int main(int argc, char **argv)
 618 {
 619         tdma_init();
 620         emit_init(3, PTE20, PullDown);
 621
 622         //pin = 1;
 623
 624         // Open serial ports
 625         sirq_dbg   = sirq_open(SIRQ_UART0, USBTX, USBRX, 115200); // to pc
 626         sirq_bbb   = sirq_open(SIRQ_UART1, PTE0,  PTE1,  115200); // to bbb
 627         sirq_mbed  = sirq_open(SIRQ_UART2, PTD3,  PTD2,  115200); // to mbed
 628
 629         // Setup timers
 630         tdma_evt   = tdma_open(TDMA_CHAN0, 3, PTC9,  PullDown); // async event
 631
 632         // mbed time sync
 633         tdma_rcv   = tdma_open(TDMA_CHAN2, 3, PTD2,  PullUp);   // time sync rcv
 634         tdma_xmt   = tdma_open(TDMA_CHAN3, 3, PTD3,  PullUp);   // time sync xmt
 635
 636         // host time sync
 637         //tdma_rcv   = tdma_open(TDMA_CHAN2, 2, USBRX, PullUp); // time sync rcv
 638         //tdma_xmt   = tdma_open(TDMA_CHAN3, 2, USBTX, PullUp); // time sync xmt
 639
 640         // start timers
 641         tdma_start(tdma_evt);
 642         tdma_start(tdma_rcv);
 643         tdma_start(tdma_xmt);
 644
 645         // Serial timestamping
 646         serial_tdma_rcv = tdma_rcv;
 647         serial_tdma_xmt = tdma_xmt;
 648
 649         // Test clocks
 650         //MCG->C1    = 0x05; // was 0x1A
 651         //MCG->C2    = 0x2C; // was 0x24
 652         //MCG->C3    = 0x91; // was 0x91
 653         //MCG->C4    = 0x10; // was 0x10
 654         //MCG->C5    = 0x01; // was 0x01
 655         //MCG->C6    = 0x40; // was 0x40
 656         //MCG->S     = 0x6E; // was 0x6E
 657         //MCG->SC    = 0x02; // was 0x02
 658         //MCG->ATCVH = 0x00; // was 0x00
 659         //MCG->ATCVL = 0x00; // was 0x00
 660         //MCG->C7    = 0x00; // was 0x00
 661         //MCG->C8    = 0x80; // was 0x80
 662         //MCG->C9    = 0x00; // was 0x00
 663         //MCG->C10   = 0x00; // was 0x00
 664
 665         //sirq_printf("MGC - C1    %02hx\r\n", MCG->C1);     // 1A
 666         //sirq_printf("MGC - C2    %02hx\r\n", MCG->C2);     // 24
 667         //sirq_printf("MGC - C3    %02hx\r\n", MCG->C3);     // 91
 668         //sirq_printf("MGC - C4    %02hx\r\n", MCG->C4);     // 10
 669         //sirq_printf("MGC - C5    %02hx\r\n", MCG->C5);     // 01
 670         //sirq_printf("MGC - C6    %02hx\r\n", MCG->C6);     // 40
 671         //sirq_printf("MGC - S     %02hx\r\n", MCG->S);      // 6E
 672         //sirq_printf("MGC - SC    %02hx\r\n", MCG->SC);     // 02
 673         //sirq_printf("MGC - ATCVH %02hx\r\n", MCG->ATCVH);  // 00
 674         //sirq_printf("MGC - ATCVL %02hx\r\n", MCG->ATCVL);  // 00
 675         //sirq_printf("MGC - C7    %02hx\r\n", MCG->C7);     // 00
 676         //sirq_printf("MGC - C8    %02hx\r\n", MCG->C8);     // 80
 677         //sirq_printf("MGC - C9    %02hx\r\n", MCG->C9);     // 00
 678         //sirq_printf("MGC - C10   %02hx\r\n", MCG->C10);    // 00
 679
 680         // Run background loop
 681         while (true)
 682                 background();
 683
 684         // Performance testing
 685         //uint64_t prev = 0, due = 0;
 686         //uint64_t worst[10] = {};
 687         //int      count = 0;
 688         //while (true) {
 689         //      uint64_t local = tdma_time();
 690         //      if (prev && (local-prev) > worst[count])
 691         //              worst[count] = (local-prev);
 692         //      prev = local;
 693         //      if (local > due) {
 694         //              if (count == 5) {
 695         //                      static char str[] = "background background background\r\n";
 696         //                      sirq_write(sirq_dbg, str, sizeof(str));
 697         //              }
 698         //              if (count == 9) {
 699         //                      sirq_printf("background\r\n");
 700         //                      for (int i = 0; i < 10; i++) {
 701         //                              sirq_printf("  worst[%d] = 0.%09u\r\n",
 702         //                                              i, worst[i]);
 703         //                              worst[i] = 0;
 704         //                      }
 705         //              }
 706         //              due += NSEC_PER_SEC;
 707         //              count = (count + 1) % 10;
 708         //      }
 709         //}
 710
 711         // Run tests
 712         //test_main();
 713
 714         return 0;
 715 }