ESP32 Setup ledc affect to wdt time

[w1zardgame]

I've got few tests with ledc and i've got strange results.

If we use ledc like this:

Code: [Select all] [Expand/Collapse]

1. void setup() {
2.   Serial.begin(115200);
3.  
4.   Serial.println(F("Start setup"));
5.  
6.   pinMode(GPIO_NUM_32, OUTPUT);
7.     pinMode(GPIO_NUM_32, LOW);
8.     ledcSetup(LEDC_CHANNEL_0, 10000000, 2 );
9.     ledcAttachPin(GPIO_NUM_32, LEDC_CHANNEL_0);
10.     ledcWrite(LEDC_CHANNEL_0, 2 );
11.  
12.   int time = 0;
13.   while(1) { Serial.println(time); delay(time++); }
14.   }

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It means I just want to generate pwm 10mhz on 32 pin. But with this configuration we have got WDT on ~10ms. And some interesting fact that esp32 reset automatically after 10ms and it happens again and again. But some time rst:0x10 (RTCWDT_RTC_RESET),boot:0x33 (SPI_FAST_FLASH_BOOT) happened thas indicate about WDT Reset.

Output example:

Code: [Select all] [Expand/Collapse]

1. 0
2. 1
3. 2
4. 3
5. 4
6. 5
7. 6
8. 7
9. 8
10. 9
11. 10
12. �Start setup
13. 0
14. 1
15. 2
16. 3
17. 4
18. 5
19. 6
20. 7
21. 8
22. 9
23. 10
24. 11
25. Start setup
26. 0
27. 1
28. 2
29. 3
30. 4
31. 5
32. 6
33. 7
34. 8
35. 9
36. 10
37. 11
38. ets Jun  8 2016 00:22:57
39.  
40. rst:0x10 (RTCWDT_RTC_RESET),boot:0x33 (SPI_FAST_FLASH_BOOT)
41. configsip: 0, SPIWP:0xee
42. clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
43. mode:DIO, clock div:2
44. load:0x3fff0018,len:4
45. load:0xffffffff,len:-1
46. ets Jun  8 2016 00:22:57

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But if we remove this code and it would be like this:

Code: [Select all] [Expand/Collapse]

1. void setup() {
2.   Serial.begin(115200);
3.  
4.   Serial.println(F("Start setup"));
5.  
6.   int sec = 0;
7.   while(1) {
8.     Serial.println(sec);
9.     delay(sec++);
10.   }
11.   }

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Counter newer stop. And any WDT errors never happens

Code: [Select all] [Expand/Collapse]

1. Start setup
2. 0
3. 1
4. 2
5. 3
6. 4
7. 5
8. 6
9. 7
10. 8
11. 9
12. 10
13. 11
14. 12
15. 13
16. 14
17. 15
18. 16
19. 17
20. 18
21. 19
22. 20
23. 21
24. .
25. .
26. .
27. 187
28. .
29. .
30. .
31. 1000
32. .
33. .
34. .

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So. What is wrong? Someone please help me