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 0
  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 static uint32_t *emit_pcr    = 0; // transmit pin name
 115
 116 static uint64_t  emit_start  = 0; // transmit start time (world time)
 117 static uint64_t  emit_period = 0; // transmit period
 118 static uint64_t  emit_due    = 0; // next transmit (world time)
 119
 120 static uint32_t  emit_slack  = 0; // how far ahead we need to schedule, in us
 121 static uint32_t  emit_worst  = 0; // worst-case latency in task table
 122
 123 void emit_init(int alt, PinName pin, PinMode mode)
 124 {
 125         // Find pin
 126         emit_pcr = (uint32_t*)(PORTA_BASE + pin);
 127
 128         // Enable clocks
 129         SIM->SCGC6            |= SIM_SCGC6_TPM1_MASK;
 130         SIM->SOPT2            |= SIM_SOPT2_TPMSRC(1);
 131
 132         // Set pin mode
 133         emit_pcr[0]            = PORT_PCR_ISF_MASK
 134                                | PORT_PCR_MUX(alt)
 135                                | mode;
 136
 137         // Setup Timer/PWM Module
 138         TPM1->SC               = TPM_SC_TOF_MASK;
 139         TPM1->CNT              = TPM_CNT_COUNT(0);
 140         TPM1->MOD              = TPM_MOD_MOD(0xFFFF);
 141
 142         TPM1->CONTROLS[0].CnSC = TPM_CnSC_CHF_MASK    // clear flag
 143                                | TPM_CnSC_MSB_MASK    // set output highon match,
 144                                | TPM_CnSC_ELSB_MASK   // cleared on overflow
 145                                | TPM_CnSC_ELSA_MASK;  // ..
 146
 147         TPM1->STATUS           = TPM_STATUS_CH0F_MASK
 148                                | TPM_STATUS_TOF_MASK;
 149
 150         TPM1->CONF             = TPM_CONF_CSOO_MASK;
 151 }
 152
 153 void emit_enable(uint64_t start, uint64_t period)
 154 {
 155         const int slack_tick = 0x8000; // tune based on emit_worst
 156
 157         emit_start  = start;
 158         emit_period = period;
 159         emit_due    = start + period;
 160
 161         emit_slack  = slack_tick * 1000 / 24;
 162
 163         time_printf("emit scheduled", emit_due);
 164 }
 165
 166 #define CLOCKS(x) ((uint16_t)((x) * 24 / 1000))
 167
 168 void emit_schedule(uint64_t when)
 169 {
 170         uint64_t now    = time_to_world(tdma_time());
 171         uint64_t start  = when - now;
 172         uint64_t stop   = start + 100000;
 173
 174         // Disable timer
 175         TPM1->SC               = TPM_SC_TOF_MASK;
 176
 177         // Set transmit time
 178         TPM1->CONTROLS[0].CnV  = CLOCKS(start);
 179         TPM1->MOD              = TPM_MOD_MOD(CLOCKS(stop));
 180
 181         // Start the timer
 182         TPM1->SC               = TPM_SC_TOF_MASK
 183                                | TPM_SC_PS(1)
 184                                | TPM_SC_CMOD(1);
 185
 186         // Debug
 187         //sirq_printf("emitting event\r\n");
 188 }
 189
 190 void emit_transmit(uint64_t local, uint64_t world)
 191 {
 192         static uint64_t prev = 0;
 193
 194         // Record how how much time we have to reschedule
 195         if (prev && (local-prev) > emit_worst)
 196                 emit_worst = (local-prev);
 197         prev = local;
 198
 199         // Schedule task if needed
 200         if (emit_due && emit_period &&
 201             world+emit_slack > emit_due) {
 202                 emit_schedule(emit_due);
 203                 emit_due += emit_period;
 204         }
 205 }
 206
 207 /************************
 208  * Serial I/O functions *
 209  ************************/
 210
 211 typedef struct {
 212         int      index;
 213         int      state;
 214         uint8_t  buffer[256];
 215 } parser_t;
 216
 217 static uint32_t serial_device_id   = 0;
 218
 219 const  uint64_t serial_sync_delay  = NSEC_PER_SEC / 100; // 1hz
 220 static uint64_t serial_sync_due    = 0;
 221
 222 static tdma_t  *serial_tdma_rcv    = NULL;
 223 static tdma_t  *serial_tdma_xmt    = NULL;
 224
 225 static uint64_t serial_prev_local  = 0;
 226 static uint64_t serial_prev_seq    = 0;
 227
 228 static uint64_t serial_xmt_local   = 0;
 229 static uint64_t serial_xmt_seq     = 0;
 230
 231 /**
 232  * Convert world to local time
 233  */
 234 uint64_t serial_read_time(ntime_t time)
 235 {
 236         return ((uint64_t)time.seconds) * NSEC_PER_SEC
 237              + ((uint64_t)time.nanosec);
 238 }
 239
 240 ntime_t serial_write_time(uint64_t time)
 241 {
 242         ntime_t buf = {};
 243         buf.seconds = time / NSEC_PER_SEC;
 244         buf.nanosec = time % NSEC_PER_SEC;
 245         return buf;
 246 }
 247
 248 /**
 249  * Output initialization message init message
 250  */
 251 void serial_send_init(uint16_t device, uint64_t local)
 252 {
 253 }
 254
 255 /**
 256  * Output time sync message
 257  */
 258 void serial_send_sync(sirq_t *port, uint64_t now)
 259 {
 260         if (serial_sync_due == 0 || now < serial_sync_due)
 261                 return; // not ready
 262
 263         //sirq_printf("sending sync\r\n");
 264
 265         // Calculate world time
 266         uint64_t local = 0;
 267         uint64_t world = time_to_world(serial_xmt_local);
 268
 269         // Message data
 270         header_t   head;
 271         sync_msg_t body;
 272
 273         // Transmit sync message
 274         head.header = MSG_HEADER;
 275         head.msgid  = MSG_ID_SYNC;
 276         head.length = sizeof(body);
 277         head.cksum  = 0; // todo
 278
 279         body.seq          = serial_xmt_seq;
 280         body.time.seconds = world / NSEC_PER_SEC;
 281         body.time.nanosec = world % NSEC_PER_SEC;
 282
 283         tdma_stop(serial_tdma_rcv);
 284
 285         tdma_start(serial_tdma_xmt);
 286         sirq_write(port, &head, sizeof(head));
 287         sirq_write(port, &body, sizeof(body));
 288         tdma_stop(serial_tdma_xmt);
 289
 290         // save transmit time
 291         int valid = tdma_stamp(serial_tdma_xmt, &local);
 292         if (!valid)
 293                 sirq_printf("sync transmit time -- missed\r\n");
 294         else
 295                 //time_printf("sync transmit time ", local);
 296
 297         tdma_start(serial_tdma_rcv);
 298
 299         serial_xmt_seq  += 1;
 300         serial_sync_due  = 0;
 301         serial_xmt_local = local;
 302 }
 303
 304 /**
 305  * Output external event received message
 306  *   event: id of the received event
 307  *   time:  compensated timestamp of the event
 308  */
 309 void serial_send_event(uint16_t event, uint64_t local)
 310 {
 311         time_printf("event received", local);
 312
 313 #if 0
 314         // Message data
 315         header_t    head;
 316         event_msg_t body;
 317
 318         uint64_t world = time_to_world(local);
 319
 320         ntime_t time = {};
 321         time.seconds = (uint32_t)(world / NSEC_PER_SEC);
 322         time.nanosec = (uint32_t)(world % NSEC_PER_SEC);
 323
 324         // Transmit sync message
 325         head.header = MSG_HEADER;
 326         head.msgid  = MSG_ID_SYNC;
 327         head.length = sizeof(body);
 328         head.cksum  = 0; // todo
 329
 330         body.seq          = serial_xmt_seq;
 331         body.time.seconds = world / NSEC_PER_SEC;
 332         body.time.nanosec = world % NSEC_PER_SEC;
 333
 334         tdma_stop(serial_tdma_rcv);
 335
 336         tdma_start(serial_tdma_xmt);
 337         sirq_write(port, &head, sizeof(head));
 338         sirq_write(port, &body, sizeof(body));
 339         tdma_stop(serial_tdma_xmt);
 340 #endif
 341 }
 342
 343 /**
 344  * Handle init message
 345  */
 346 void serial_handle_init(init_msg_t *msg)
 347 {
 348         sirq_printf("initialize: %s %s %s %s %s\r\n",
 349                 msg->valid & MSG_VALID_DEVICE ? "DEV"    : "dev",
 350                 msg->valid & MSG_VALID_START  ? "START"  : "start",
 351                 msg->valid & MSG_VALID_PERIOD ? "PERIOD" : "period",
 352                 msg->valid & MSG_VALID_WORLD  ? "WORLD"  : "world",
 353                 msg->valid & MSG_VALID_SYNC   ? "SYNC"   : "sync");
 354         sirq_printf("  dev    -- %d\r\n", msg->device);
 355         time_printf("  start ", serial_read_time(msg->start));
 356         time_printf("  period", serial_read_time(msg->period));
 357         time_printf("  world ", serial_read_time(msg->world));
 358
 359         if (msg->valid & MSG_VALID_DEVICE)
 360                 serial_device_id = msg->device;
 361
 362         if (msg->valid & MSG_VALID_START ||
 363             msg->valid & MSG_VALID_PERIOD) {
 364                 uint64_t start  = serial_read_time(msg->start);
 365                 uint64_t period = serial_read_time(msg->period);
 366                 emit_enable(start, period);
 367         }
 368
 369         if (msg->valid & MSG_VALID_WORLD) {
 370                 uint64_t world = serial_read_time(msg->world);
 371                 uint64_t local = tdma_time();
 372                 time_ext_init(local, world);
 373         }
 374
 375         if (msg->valid & MSG_VALID_SYNC)
 376                 serial_sync_due = tdma_time() + serial_sync_delay;
 377 }
 378
 379 /**
 380  * Handle sync message
 381  */
 382 void serial_handle_sync(sync_msg_t *msg)
 383 {
 384         // Read receive timestamp for next time sync message
 385         uint64_t current = 0;
 386         int valid = tdma_stamp(serial_tdma_rcv, &current);
 387         if (!valid)
 388                 sirq_printf("sync receive time  -- missing\r\n");
 389         //else
 390         //      time_printf("sync receive time ", current);
 391         tdma_stop(serial_tdma_rcv);
 392
 393         // Lookup times
 394         uint64_t world = ((uint64_t)msg->time.seconds) * NSEC_PER_SEC
 395                        + ((uint64_t)msg->time.nanosec);
 396
 397         // Valid times timestamp
 398         if (serial_prev_seq == (msg->seq-1)) {
 399                 uint64_t local = serial_prev_local;
 400                 time_ext_sync(local, world);
 401         }
 402
 403         // Queue transmit to other board
 404         serial_sync_due   = tdma_time() + serial_sync_delay;
 405
 406         // Update states
 407         serial_prev_local = current;
 408         serial_prev_seq   = msg->seq;
 409 }
 410
 411 /**
 412  * Handle event message
 413  */
 414 void serial_handle_event(event_msg_t *msg)
 415 {
 416 }
 417
 418 /**
 419  * Deliver message
 420  */
 421 void serial_deliver(int msgid, void *body)
 422 {
 423         switch (msgid) {
 424                 case MSG_ID_INIT:
 425                         //sirq_printf("received init msg\r\n");
 426                         serial_handle_init((init_msg_t*)body);
 427                         break;
 428                 case MSG_ID_SYNC:
 429                         //sirq_printf("received sync msg\r\n");
 430                         serial_handle_sync((sync_msg_t*)body);
 431                         break;
 432                 case MSG_ID_EVENT:
 433                         //sirq_printf("received event msg\r\n");
 434                         serial_handle_event((event_msg_t*)body);
 435                         break;
 436         }
 437 }
 438
 439 /**
 440  * Process serial receive messages
 441  */
 442 void serial_receive(parser_t *parser, int byte)
 443 {
 444         //sirq_printf("serial_receive - %02x\r\n", byte);
 445
 446         // Lookup pointers
 447         header_t *head = (header_t*)parser->buffer;
 448         void     *body = (void*)(head+1);
 449         const int max_length = sizeof(parser->buffer)-sizeof(header_t);
 450
 451         // Process uart messages
 452         parser->buffer[parser->index++] = byte;
 453         switch (parser->state) {
 454                 case 0: // Search
 455                         if (parser->index == sizeof(uint16_t)) {
 456                                 if (head->header == MSG_HEADER) {
 457                                         parser->state = 1;
 458                                 } else {
 459                                         parser->buffer[0] = parser->buffer[1];
 460                                         parser->index = 1;
 461                                 }
 462                         }
 463                         break;
 464                 case 1: // Header
 465                         if (parser->index == sizeof(header_t)) {
 466                                 if (head->length <= max_length &&
 467                                     head->msgid  <= MSG_MAX_ID) {
 468                                         parser->state = 2;
 469                                 } else {
 470                                         parser->index = 0;
 471                                         parser->state = 0;
 472                                 }
 473                         }
 474                         break;
 475                 case 2: // Data
 476                         if (parser->index == (int)sizeof(header_t)+head->length) {
 477                                 serial_deliver(head->msgid, body);
 478                                 parser->index = 0;
 479                                 parser->state = 0;
 480                         }
 481                         break;
 482         }
 483 }
 484
 485 /********************
 486  * Data definitions *
 487  ********************/
 488
 489 // LEDs
 490 DigitalOut led1(LED1);
 491 DigitalOut led2(LED2);
 492
 493 // Message Parsers
 494 parser_t   parser_dbg;
 495 parser_t   parser_bbb;
 496 parser_t   parser_mbed;
 497
 498 // Serial IRQ
 499 sirq_t    *sirq_dbg;
 500 sirq_t    *sirq_bbb;
 501 sirq_t    *sirq_mbed;
 502
 503 // Timer DMA
 504 tdma_t    *tdma_evt;
 505 tdma_t    *tdma_rcv;
 506 tdma_t    *tdma_xmt;
 507
 508 /*********
 509  * Tasks *
 510  *********/
 511
 512 void task_serial(uint64_t local, uint64_t world)
 513 {
 514         while (sirq_ready(sirq_dbg)) {
 515                 //sirq_printf("serial recv - dbg\r\n");
 516                 serial_receive(&parser_dbg,  sirq_getc(sirq_dbg));
 517         }
 518
 519         while (sirq_ready(sirq_bbb)) {
 520                 //sirq_printf("serial recv - bbb\r\n");
 521                 serial_receive(&parser_bbb,  sirq_getc(sirq_bbb));
 522         }
 523
 524         while (sirq_ready(sirq_mbed)) {
 525                 //sirq_printf("serial recv - mbed\r\n");
 526                 serial_receive(&parser_mbed, sirq_getc(sirq_mbed));
 527         }
 528 }
 529
 530 void task_events(uint64_t local, uint64_t world)
 531 {
 532         uint64_t event = 0;
 533
 534 #ifdef VERBOSE
 535         if (tdma_stamp(tdma_evt, &event)) {
 536                 sirq_printf("event received - evt\r\n");
 537         if (tdma_stamp(tdma_rcv, &event))
 538                 sirq_printf("event received - rcv\r\n");
 539         if (tdma_stamp(tdma_xmt, &event))
 540                 sirq_printf("event received - xmt\r\n");
 541 #endif
 542
 543         if (tdma_stamp(tdma_evt, &event))
 544                 serial_send_event(0, event);
 545         tdma_stop(tdma_evt);
 546         tdma_start(tdma_evt);
 547 }
 548
 549 void task_sync(uint64_t local, uint64_t world)
 550 {
 551         serial_send_sync(sirq_mbed, local);
 552 }
 553
 554 void task_leds(uint64_t local, uint64_t world)
 555 {
 556         static uint32_t which = 0;
 557         led1 = (which == 0);
 558         led2 = (which == 1);
 559         which ^= 1;
 560 }
 561
 562 void task_emit(uint64_t local, uint64_t world)
 563 {
 564         emit_transmit(local, world);
 565 }
 566
 567 void task_debug(uint64_t local, uint64_t world)
 568 {
 569         //tdma_debug(tdma_rcv);
 570         //tdma_debug(tdma_xmt);
 571
 572         //sirq_debug(sirq_mbed);
 573
 574 #ifdef VERBOSE
 575         sirq_printf("background - %6u.%02u -> %u.%02u\r\n",
 576                         (uint32_t)(local / NSEC_PER_SEC),
 577                         (uint32_t)(local % NSEC_PER_SEC / 10000000),
 578                         (uint32_t)(world / NSEC_PER_SEC),
 579                         (uint32_t)(world % NSEC_PER_SEC / 10000000));
 580 #endif
 581 }
 582
 583 /********
 584  * Main *
 585  ********/
 586
 587 #define N_ELEM(x) (sizeof(x) / sizeof((x)[0]))
 588
 589 extern void test_main(void);
 590 extern serial_t stdio_uart;
 591
 592 static struct {
 593         void (*task)(uint64_t, uint64_t);
 594         uint64_t period;
 595         uint64_t due;
 596 } tasks[] = {
 597         { task_serial, 0          }, // always
 598         { task_events, 0          }, // always -- testing
 599         { task_sync,   0          }, // always
 600         { task_emit,   0          }, // always
 601         { task_leds,   100000000  }, // 10hz
 602         { task_debug,  1000000000 }, // 1hz
 603 };
 604
 605 void background(void)
 606 {
 607         // Debugging
 608         uint64_t local = tdma_time();
 609         uint64_t world = time_to_world(local);
 610
 611         // Run the scheduler
 612         for (unsigned i = 0; i < N_ELEM(tasks); i++) {
 613                 if (local >= tasks[i].due) {
 614                         tasks[i].task(local, world);
 615                         tasks[i].due += tasks[i].period;
 616                 }
 617         }
 618 }
 619
 620 int main(int argc, char **argv)
 621 {
 622         tdma_init();
 623         emit_init(3, PTE20, PullDown);
 624
 625         //pin = 1;
 626
 627         // Open serial ports
 628         sirq_dbg   = sirq_open(SIRQ_UART0, USBTX, USBRX, 115200); // to pc
 629         sirq_bbb   = sirq_open(SIRQ_UART1, PTE0,  PTE1,  115200); // to bbb
 630         sirq_mbed  = sirq_open(SIRQ_UART2, PTD3,  PTD2,  115200); // to mbed
 631
 632         // Setup timers
 633         tdma_evt   = tdma_open(TDMA_CHAN0, 3, PTC9,  PullDown); // async event
 634
 635         // mbed time sync
 636         tdma_rcv   = tdma_open(TDMA_CHAN2, 3, PTD2,  PullUp);   // time sync rcv
 637         tdma_xmt   = tdma_open(TDMA_CHAN3, 3, PTD3,  PullUp);   // time sync xmt
 638
 639         // host time sync
 640         //tdma_rcv   = tdma_open(TDMA_CHAN2, 2, USBRX, PullUp); // time sync rcv
 641         //tdma_xmt   = tdma_open(TDMA_CHAN3, 2, USBTX, PullUp); // time sync xmt
 642
 643         // start timers
 644         tdma_start(tdma_evt);
 645         tdma_start(tdma_rcv);
 646         tdma_start(tdma_xmt);
 647
 648         // Serial timestamping
 649         serial_tdma_rcv = tdma_rcv;
 650         serial_tdma_xmt = tdma_xmt;
 651
 652         // Test clocks
 653         //MCG->C1    = 0x05; // was 0x1A
 654         //MCG->C2    = 0x2C; // was 0x24
 655         //MCG->C3    = 0x91; // was 0x91
 656         //MCG->C4    = 0x10; // was 0x10
 657         //MCG->C5    = 0x01; // was 0x01
 658         //MCG->C6    = 0x40; // was 0x40
 659         //MCG->S     = 0x6E; // was 0x6E
 660         //MCG->SC    = 0x02; // was 0x02
 661         //MCG->ATCVH = 0x00; // was 0x00
 662         //MCG->ATCVL = 0x00; // was 0x00
 663         //MCG->C7    = 0x00; // was 0x00
 664         //MCG->C8    = 0x80; // was 0x80
 665         //MCG->C9    = 0x00; // was 0x00
 666         //MCG->C10   = 0x00; // was 0x00
 667
 668         //sirq_printf("MGC - C1    %02hx\r\n", MCG->C1);     // 1A
 669         //sirq_printf("MGC - C2    %02hx\r\n", MCG->C2);     // 24
 670         //sirq_printf("MGC - C3    %02hx\r\n", MCG->C3);     // 91
 671         //sirq_printf("MGC - C4    %02hx\r\n", MCG->C4);     // 10
 672         //sirq_printf("MGC - C5    %02hx\r\n", MCG->C5);     // 01
 673         //sirq_printf("MGC - C6    %02hx\r\n", MCG->C6);     // 40
 674         //sirq_printf("MGC - S     %02hx\r\n", MCG->S);      // 6E
 675         //sirq_printf("MGC - SC    %02hx\r\n", MCG->SC);     // 02
 676         //sirq_printf("MGC - ATCVH %02hx\r\n", MCG->ATCVH);  // 00
 677         //sirq_printf("MGC - ATCVL %02hx\r\n", MCG->ATCVL);  // 00
 678         //sirq_printf("MGC - C7    %02hx\r\n", MCG->C7);     // 00
 679         //sirq_printf("MGC - C8    %02hx\r\n", MCG->C8);     // 80
 680         //sirq_printf("MGC - C9    %02hx\r\n", MCG->C9);     // 00
 681         //sirq_printf("MGC - C10   %02hx\r\n", MCG->C10);    // 00
 682
 683         // Run background loop
 684         while (true)
 685                 background();
 686
 687         // Performance testing
 688         //uint64_t prev = 0, due = 0;
 689         //uint64_t worst[10] = {};
 690         //int      count = 0;
 691         //while (true) {
 692         //      uint64_t local = tdma_time();
 693         //      if (prev && (local-prev) > worst[count])
 694         //              worst[count] = (local-prev);
 695         //      prev = local;
 696         //      if (local > due) {
 697         //              if (count == 5) {
 698         //                      static char str[] = "background background background\r\n";
 699         //                      sirq_write(sirq_dbg, str, sizeof(str));
 700         //              }
 701         //              if (count == 9) {
 702         //                      sirq_printf("background\r\n");
 703         //                      for (int i = 0; i < 10; i++) {
 704         //                              sirq_printf("  worst[%d] = 0.%09u\r\n",
 705         //                                              i, worst[i]);
 706         //                              worst[i] = 0;
 707         //                      }
 708         //              }
 709         //              due += NSEC_PER_SEC;
 710         //              count = (count + 1) % 10;
 711         //      }
 712         //}
 713
 714         // Run tests
 715         //test_main();
 716
 717         return 0;
 718 }