return time_last_world + elapsed;
}
+uint64_t time_to_local(uint64_t world)
+{
+ uint64_t elapsed = world - time_last_world;
+ return time_last_local + elapsed;
+}
+
/**
* Synchronize the timer internal state with updates
* from an external time sync message.
world = time_last_world;
//#ifdef VERBOSE
-#if 1
+#if 0
uint64_t error = world > guess ? world - guess :
guess > world ? guess - world : 0;
int ahead = guess > world;
* Signal generation *
*********************/
-#define EMIT_CLOCKS(nsec) ((uint16_t)((nsec) * 24 / 1000))
-#define EMIT_NSEC(clocks) ((uint16_t)((clocks) * 1000 / 24))
+// for 50 Mhz clock 50/1000 = 1/20 (PLL/2)
+
+// for 48 Mhz clock 48/1000 = 6/125 (FLL)
+// for 24 Mhz clock, 24/1000 = 3/125
+// for 12 Mhz clock, 12/1000 = 3/250
+// for 6 Mhz clock, 6/1000 = 3/500
+// for 3 Mhz clock, 3/1000 = 3/1000
+
+#define EMIT_PS 1
+
+//#if EMIT_PS == 0
+//#define EMIT_CLOCKS(nsec) ((uint16_t)((nsec) / 20))
+//#define EMIT_NSEC(clocks) ((uint16_t)((clocks) * 20))
+
+#if EMIT_PS == 0
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 6 / 125))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 125 / 6))
+#elif EMIT_PS == 1
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 125))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 125 / 3))
+#elif EMIT_PS == 2
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 250))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 250 / 3))
+#elif EMIT_PS == 3
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 500))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 500 / 3))
+#elif EMIT_PS == 4
+#define EMIT_CLOCKS(nsec) ((uint32_t)((nsec) * 3 / 1000))
+#define EMIT_NSEC(clocks) ((uint32_t)((clocks) * 1000 / 3))
+#endif
static uint32_t *emit_pcr = 0; // transmit pin name
SIM->SCGC6 |= SIM_SCGC6_TPM1_MASK;
SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1);
+ // Reset PLL Source
+ //SIM->SOPT2 &= ~SIM_SOPT2_PLLFLLSEL_MASK;
+
+ // Debug print on SOPT2
+ // -- mbed may set PLLFLL when configuring UART0
+ // SOPT2: u0src=1 tpmsrc=1 USBSRC PLL/2 clkos=0 rtcos
+ sirq_printf("SOPT2: u0src=%d tpmsrc=%d %s %s clkos=%d %s\r\n",
+ (SIM->SOPT2 & SIM_SOPT2_UART0SRC_MASK) >> SIM_SOPT2_UART0SRC_SHIFT,
+ (SIM->SOPT2 & SIM_SOPT2_TPMSRC_MASK) >> SIM_SOPT2_TPMSRC_SHIFT,
+ (SIM->SOPT2 & SIM_SOPT2_UART0SRC_MASK) ? "USBSRC" : "usbsrc",
+ (SIM->SOPT2 & SIM_SOPT2_PLLFLLSEL_MASK) ? "PLL/2" : "FLL",
+ (SIM->SOPT2 & SIM_SOPT2_CLKOUTSEL_MASK) >> SIM_SOPT2_CLKOUTSEL_SHIFT,
+ (SIM->SOPT2 & SIM_SOPT2_RTCCLKOUTSEL_MASK) ? "RTCOS" : "rtcos");
+
// Set pin mode
emit_pcr[0] = PORT_PCR_ISF_MASK
| PORT_PCR_MUX(alt)
void emit_enable(uint64_t start, uint64_t period)
{
- const int slack_clocks = 0x8000; // tune based on emit_worst
+ const int slack_clocks = 0x4000; // tune based on emit_worst
emit_start = start;
emit_period = period;
emit_due = start + period;
- // TODO - tune slack time
- // TODO - check clock power
- // TODO - TPM clock source
emit_slack = EMIT_NSEC(slack_clocks);
time_printf("emit scheduled", emit_due);
void emit_schedule(uint64_t when)
{
- uint64_t now = time_to_world(tdma_time());
- uint64_t start = when - now; // transmit time
- uint64_t stop = start + 100000; // 100 us pulse
+ uint64_t local = time_to_local(when) * 3 / 125;
+ uint32_t width = EMIT_CLOCKS(10000);
// Disable timer
TPM1->SC = TPM_SC_TOF_MASK;
+ __disable_irq();
+
+ uint64_t now = ((uint64_t)~PIT->LTMR64H << 32)
+ | ((uint64_t)~PIT->LTMR64L);
+ uint32_t delta = local - now;
+ uint32_t start = delta >> (EMIT_PS-1); // convert to clocks
+ uint32_t stop = start + width; // end time
+
// Set transmit time
- TPM1->CONTROLS[0].CnV = EMIT_CLOCKS(start);
- TPM1->MOD = TPM_MOD_MOD(EMIT_CLOCKS(stop));
+ TPM1->CONTROLS[0].CnV = start;
+ TPM1->MOD = TPM_MOD_MOD(stop);
// Start the timer
TPM1->SC = TPM_SC_TOF_MASK
- | TPM_SC_PS(1)
+ | TPM_SC_PS(EMIT_PS)
| TPM_SC_CMOD(1);
+ __enable_irq();
+
+ // Test
+ //int64_t cnv = TPM1->CONTROLS[0].CnV;
+ //int64_t mod = TPM1->MOD;
+ //int64_t due = local - tdma_time();
+ //sirq_printf("%6d -- cnv=%04x mod=%04x due=%04x start=%04x\r\n",
+ // (int)(cnv - EMIT_CLOCKS(due)),
+ // (int)cnv, (int)mod,
+ // (int)EMIT_CLOCKS(due), EMIT_CLOCKS(start));
+
+ // Clock testing
+ //uint32_t test_tpm0 = TPM1->CNT;
+ //uint32_t test_pit0 = ~PIT->CHANNEL[0].CVAL;
+ //for (int i = 0; i < 100; i++)
+ // asm("nop");
+ //uint32_t test_tpm1 = TPM1->CNT;
+ //uint32_t test_pit1 = ~PIT->CHANNEL[0].CVAL;
+
+ //uint32_t test_tpm = test_tpm1 - test_tpm0;
+ //uint32_t test_pit = test_pit1 - test_pit0;
+ //sirq_printf("pit/tpm: %d - tpm=%08x/%08x=%d pit=%08x/%08x=%d\r\n",
+ // test_tpm - test_pit,
+ // test_tpm0, test_tpm1, test_tpm,
+ // test_pit0, test_pit1, test_pit);
+
// Debug output
- //sirq_printf("emitting event\r\n");
+ //time_printf("emitting event", when);
}
void emit_transmit(uint64_t local, uint64_t world)
static uint32_t serial_device_id = 0;
-const uint64_t serial_sync_delay = NSEC_PER_SEC / 100; // 1hz
+const uint64_t serial_sync_delay = NSEC_PER_SEC / 100;
static uint64_t serial_sync_due = 0;
static tdma_t *serial_tdma_rcv = NULL;
static tdma_t *serial_tdma_xmt = NULL;
-static uint64_t serial_prev_local = 0;
-static uint64_t serial_prev_seq = 0;
-
-static uint64_t serial_xmt_local = 0;
-static uint64_t serial_xmt_seq = 0;
-
/**
* Convert world to local time
*/
return buf;
}
+int serial_time_stamp(tdma_t *port, uint64_t *local, uint64_t *world,
+ const char *msg)
+{
+ int valid = tdma_stamp(port, local);
+ *world = time_to_world(*local);
+
+ if (!valid)
+ sirq_printf("%s -- missing\r\n", msg);
+ //else
+ // time_printf(msg, current);
+
+ return valid;
+}
+
/**
* Output initialization message init message
*/
if (serial_sync_due == 0 || now < serial_sync_due)
return; // not ready
- //sirq_printf("sending sync\r\n");
-
- // Calculate world time
- uint64_t local = 0;
- uint64_t world = time_to_world(serial_xmt_local);
-
// Message data
header_t head;
sync_msg_t body;
- // Transmit sync message
+ // Write header
head.header = MSG_HEADER;
head.msgid = MSG_ID_SYNC;
head.length = sizeof(body);
head.cksum = 0; // todo
- body.seq = serial_xmt_seq;
- body.time.seconds = world / NSEC_PER_SEC;
- body.time.nanosec = world % NSEC_PER_SEC;
-
- tdma_stop(serial_tdma_rcv);
-
+ tdma_stop(serial_tdma_rcv, 0);
tdma_start(serial_tdma_xmt);
- sirq_write(port, &head, sizeof(head));
- sirq_write(port, &body, sizeof(body));
- tdma_stop(serial_tdma_xmt);
- // save transmit time
- int valid = tdma_stamp(serial_tdma_xmt, &local);
- if (!valid)
- sirq_printf("sync transmit time -- missed\r\n");
- else
- //time_printf("sync transmit time ", local);
+ sirq_write(port, &head, sizeof(head));
+ tdma_stop(serial_tdma_xmt, 100);
tdma_start(serial_tdma_rcv);
- serial_xmt_seq += 1;
+ // Save transmit time
+ uint64_t local = 0, world = 0;
+ serial_time_stamp(serial_tdma_xmt, &local, &world,
+ "sync time transmit");
+
+ // Debug output
+ //sirq_printf("sync time transmit\r\n");
+ //time_printf(" local", local);
+ //time_printf(" world", world);
+
+ // Write body with updated time and send
+ body.time = serial_write_time(world);
+
+ sirq_write(port, &body, sizeof(body));
+
+ // Queue next transmit time
serial_sync_due = 0;
- serial_xmt_local = local;
}
/**
*/
void serial_send_event(sirq_t *port, uint16_t event, uint64_t local)
{
- time_printf("event received", local);
+ //time_printf("event received", local);
// Convert timestamp
uint64_t world = time_to_world(local);
- ntime_t ntime = serial_write_time(world);
+ ntime_t ltime = serial_write_time(local);
+ ntime_t wtime = serial_write_time(world);
// Message data
header_t head = {};
body.device = serial_device_id;
body.event = event;
- body.time = ntime;
+ body.world = wtime;
+ body.local = ltime;
// Transmit message to BBB
sirq_write(port, &head, sizeof(head));
*/
void serial_handle_sync(sync_msg_t *msg)
{
- // Read receive timestamp for next time sync message
- uint64_t current = 0;
- int valid = tdma_stamp(serial_tdma_rcv, ¤t);
- if (!valid)
- sirq_printf("sync receive time -- missing\r\n");
- //else
- // time_printf("sync receive time ", current);
- tdma_stop(serial_tdma_rcv);
+ // Read receive timestamp
+ uint64_t local = 0, world = 0;
+ serial_time_stamp(serial_tdma_rcv, &local, &world,
+ "sync time receive ");
+ tdma_stop(serial_tdma_rcv, 0);
- // Lookup times
- uint64_t world = ((uint64_t)msg->time.seconds) * NSEC_PER_SEC
- + ((uint64_t)msg->time.nanosec);
+ // Lookup reference time from message
+ uint64_t reference = serial_read_time(msg->time);
- // Valid times timestamp
- if (serial_prev_seq == (msg->seq-1)) {
- uint64_t local = serial_prev_local;
- time_ext_sync(local, world);
- }
+ // Debug output
+ //sirq_printf("sync time receive\r\n");
+ //time_printf(" local", local);
+ //time_printf(" world", world);
+ //time_printf(" ref ", reference);
+
+ // Synchronize the clocks
+ time_ext_sync(local, reference);
// Queue transmit to other board
serial_sync_due = tdma_time() + serial_sync_delay;
-
- // Update states
- serial_prev_local = current;
- serial_prev_seq = msg->seq;
}
/**
if (tdma_stamp(tdma_evt, &event))
serial_send_event(sirq_bbb, 0, event);
- tdma_stop(tdma_evt);
+ tdma_stop(tdma_evt, 0);
tdma_start(tdma_evt);
}
//sirq_debug(sirq_mbed);
+ //serial_send_event(sirq_bbb, 1, local);
+
#ifdef VERBOSE
sirq_printf("background - %6u.%02u -> %u.%02u\r\n",
(uint32_t)(local / NSEC_PER_SEC),
int main(int argc, char **argv)
{
tdma_init();
- emit_init(3, PTE20, PullDown);
//pin = 1;
serial_tdma_rcv = tdma_rcv;
serial_tdma_xmt = tdma_xmt;
- // Test clocks
- //MCG->C1 = 0x05; // was 0x1A
- //MCG->C2 = 0x2C; // was 0x24
- //MCG->C3 = 0x91; // was 0x91
- //MCG->C4 = 0x10; // was 0x10
- //MCG->C5 = 0x01; // was 0x01
- //MCG->C6 = 0x40; // was 0x40
- //MCG->S = 0x6E; // was 0x6E
- //MCG->SC = 0x02; // was 0x02
- //MCG->ATCVH = 0x00; // was 0x00
- //MCG->ATCVL = 0x00; // was 0x00
- //MCG->C7 = 0x00; // was 0x00
- //MCG->C8 = 0x80; // was 0x80
- //MCG->C9 = 0x00; // was 0x00
- //MCG->C10 = 0x00; // was 0x00
-
- //sirq_printf("MGC - C1 %02hx\r\n", MCG->C1); // 1A
- //sirq_printf("MGC - C2 %02hx\r\n", MCG->C2); // 24
- //sirq_printf("MGC - C3 %02hx\r\n", MCG->C3); // 91
- //sirq_printf("MGC - C4 %02hx\r\n", MCG->C4); // 10
- //sirq_printf("MGC - C5 %02hx\r\n", MCG->C5); // 01
- //sirq_printf("MGC - C6 %02hx\r\n", MCG->C6); // 40
- //sirq_printf("MGC - S %02hx\r\n", MCG->S); // 6E
- //sirq_printf("MGC - SC %02hx\r\n", MCG->SC); // 02
- //sirq_printf("MGC - ATCVH %02hx\r\n", MCG->ATCVH); // 00
- //sirq_printf("MGC - ATCVL %02hx\r\n", MCG->ATCVL); // 00
- //sirq_printf("MGC - C7 %02hx\r\n", MCG->C7); // 00
- //sirq_printf("MGC - C8 %02hx\r\n", MCG->C8); // 80
- //sirq_printf("MGC - C9 %02hx\r\n", MCG->C9); // 00
- //sirq_printf("MGC - C10 %02hx\r\n", MCG->C10); // 00
+ // Setup event generation
+ emit_init(3, PTE20, PullDown);
// Run background loop
while (true)
background();
- // Performance testing
- //uint64_t prev = 0, due = 0;
- //uint64_t worst[10] = {};
- //int count = 0;
- //while (true) {
- // uint64_t local = tdma_time();
- // if (prev && (local-prev) > worst[count])
- // worst[count] = (local-prev);
- // prev = local;
- // if (local > due) {
- // if (count == 5) {
- // static char str[] = "background background background\r\n";
- // sirq_write(sirq_dbg, str, sizeof(str));
- // }
- // if (count == 9) {
- // sirq_printf("background\r\n");
- // for (int i = 0; i < 10; i++) {
- // sirq_printf(" worst[%d] = 0.%09u\r\n",
- // i, worst[i]);
- // worst[i] = 0;
- // }
- // }
- // due += NSEC_PER_SEC;
- // count = (count + 1) % 10;
- // }
- //}
-
// Run tests
//test_main();