Mengenal System Clock pada Mikrokontroler AVR

Jenis2 Rangkaian Oscillator

Rangkaian Crystal Oscillator

Rangkaian RC External

Rangkaian Clock External

Setting Fuse Bit pada mikrokontroler AVR At Mega:

1. Ext. Clock; Start-up time: 6 CK + 0 ms (HIGH: 0xFF dan LOW: 0xCO);
2. Ext. Clock; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xDO);
3. Ext. Clock; Start-up time: 6 CK + 64 ms (HIGH: 0xFF dan LOW: 0xEO);
4. Int. RC Osc. 1 MHz; Start-up time: 6 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC1);
5. Int. RC Osc. 1 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD1);
6. Int. RC Osc. 1 MHz; Start-up time: 6 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE1);
7. Int. RC Osc. 2 MHz; Start-up time: 6 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC2);
8. Int. RC Osc. 2 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD2);
9. Int. RC Osc. 2 MHz; Start-up time: 6 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE2);
10. Int. RC Osc. 4 MHz; Start-up time: 6 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC3);
11. Int. RC Osc. 4 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD3);
12. Int. RC Osc. 4 MHz; Start-up time: 6 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE3);
13. Int. RC Osc. 8 MHz; Start-up time: 6 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC4);
14. Int. RC Osc. 8 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD4);
15. Int. RC Osc. 8 MHz; Start-up time: 6 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE4);
16. Ext. RC Osc.         -  0.9 MHz; Start-up time: 18 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC5);
17. Ext. RC Osc.         -  0.9 MHz; Start-up time: 18 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD5);
18. Ext. RC Osc.         -  0.9 MHz; Start-up time: 18 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE5);
19. Ext. RC Osc.         -  0.9 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xF5);
20. Ext. RC Osc. 0.9 MHz -  3.0 MHz; Start-up time: 18 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC6);
21. Ext. RC Osc. 0.9 MHz -  3.0 MHz; Start-up time: 18 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD6);
22. Ext. RC Osc. 0.9 MHz -  3.0 MHz; Start-up time: 18 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE6);
23. Ext. RC Osc. 0.9 MHz -  3.0 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xF6);
24. Ext. RC Osc. 3.0 MHz -  8.0 MHz; Start-up time: 18 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC7);
25. Ext. RC Osc. 3.0 MHz -  8.0 MHz; Start-up time: 18 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD7);
26. Ext. RC Osc. 3.0 MHz -  8.0 MHz; Start-up time: 18 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE7);
27. Ext. RC Osc. 3.0 MHz -  8.0 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xF7);
28. Ext. RC Osc. 8.0 MHz -  12.0 MHz; Start-up time: 18 CK + 0 ms (HIGH: 0xFF dan LOW: 0xC8);
29. Ext. RC Osc. 8.0 MHz -  12.0 MHz; Start-up time: 18 CK + 4 ms (HIGH: 0xFF dan LOW: 0xD8);
30. Ext. RC Osc. 8.0 MHz -  12.0 MHz; Start-up time: 18 CK + 64 ms (HIGH: 0xFF dan LOW: 0xE8);
31. Ext. RC Osc. 8.0 MHz -  12.0 MHz; Start-up time: 6 CK + 4 ms (HIGH: 0xFF dan LOW: 0xF8);
32. Ext. Low-Freq. Crystal; Start-up time: 1K CK + 4 ms (HIGH: 0xFF dan LOW: 0xC9);
33. Ext. Low-Freq. Crystal; Start-up time: 1K CK + 64 ms (HIGH: 0xFF dan LOW: 0xD9);
34. Ext. Low-Freq. Crystal; Start-up time: 32K CK + 64 ms (HIGH: 0xFF dan LOW: 0xE9);
35. Ext. Crystal/Resonator Low Freq.; Start-up time: 258 CK + 4 ms (HIGH: 0xFF dan LOW: 0xCA);
36. Ext. Crystal/Resonator Low Freq.; Start-up time: 258 CK + 64 ms (HIGH: 0xFF dan LOW: 0xDA);
37. Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 0 ms (HIGH: 0xFF dan LOW: 0xEA);
38. Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 4 ms (HIGH: 0xFF dan LOW: 0xFA);
39. Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 64 ms (HIGH: 0xFF dan LOW: 0xCB);
40. Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 0 ms (HIGH: 0xFF dan LOW: 0xDB);
41. Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 4 ms (HIGH: 0xFF dan LOW: 0xEB);
42. Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 64 ms (HIGH: 0xFF dan LOW: 0xFB);
43. Ext. Crystal/Resonator Medium Freq.; Start-up time: 258 CK + 4 ms (HIGH: 0xFF dan LOW: 0xCC);
44. Ext. Crystal/Resonator Medium Freq.; Start-up time: 258 CK + 64 ms (HIGH: 0xFF dan LOW: 0xDC);
45. Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 0 ms (HIGH: 0xFF dan LOW: 0xEC);
46. Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 4 ms (HIGH: 0xFF dan LOW: 0xFC);
47. Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 64 ms (HIGH: 0xFF dan LOW: 0xCD);
48. Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 0 ms (HIGH: 0xFF dan LOW: 0xDD);
49. Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 4 ms (HIGH: 0xFF dan LOW: 0xED);
50. Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 64 ms (HIGH: 0xFF dan LOW: 0xFD);
51. Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 4 ms (HIGH: 0xFF dan LOW: 0xCE);
52. Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 64 ms (HIGH: 0xFF dan LOW: 0xDE);
53. Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 0 ms (HIGH: 0xFF dan LOW: 0xEE);
54. Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 4 ms (HIGH: 0xFF dan LOW: 0xFE);
55. Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 64 ms (HIGH: 0xFF dan LOW: 0xCF);
56. Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 0 ms (HIGH: 0xFF dan LOW: 0xDF);
57. Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 4 ms (HIGH: 0xFF dan LOW: 0xEF);
58. Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 64 ms (HIGH: 0xFF dan LOW: 0xFF);

Semoga bermanfaat dan selamat mencoba, hati-hati dengan pilihan External, karena setelah Anda mengatur pilihan ke External, maka Anda harus menyediakan sumber clock eksternal sesuai dengan pengaturan yang dilakukan, jika tidak, maka AVR Anda tidak dapat di-program lagi (masih berfungsi tetapi seperti mengunci diri, padahal tidak diotak-atik Lock bit-nya).
Sumber

untuk lebih gampangnya, ada program yang bisa langsung menghitung secara online, berikut link-nya
 AVR Fuse Calculator