S.M.P.T.E. - Code

Contents:

[Document Version: 1.00] [Last Updated: Oct_09_1995]


Chapter 1) About the Author

Author: Bob Harvey
E-Mail: rdh@cts.com
Date: 09 Oct 1995


Chapter 2) SMPTE Time Code 80-Bit Longitudinal Bit Assignments

BIT) description

  1. 1 BCD Frames Units
  2. 2 BCD Frames Units
  3. 4 BCD Frames Units
  4. 8 BCD Frames Units
  5. Bit 0 of 1st Binary Group (User Bits)
  6. Bit 1 of 1st Binary Group (User Bits)
  7. Bit 2 of 1st Binary Group (User Bits)
  8. Bit 3 of 1st Binary Group (User Bits)
  9. 10 BCD Frames Tens
  10. 20 BCD Frames Tens
  11. Drop Frame Flag Bit
  12. Color Frame Flag Bit
  13. Bit 0 of 2nd Binary Group (User Bits)
  14. Bit 1 of 2nd Binary Group (User Bits)
  15. Bit 2 of 2nd Binary Group (User Bits)
  16. Bit 3 of 2nd Binary Group (User Bits)
  17. 1 BCD Seconds Units
  18. 2 BCD Seconds Units
  19. 4 BCD Seconds Units
  20. 8 BCD Seconds Units
  21. Bit 0 of 3rd Binary Group (User Bits)
  22. Bit 1 of 3rd Binary Group (User Bits)
  23. Bit 2 of 3rd Binary Group (User Bits)
  24. Bit 3 of 3rd Binary Group (User Bits)
  25. 10 BCD Seconds Tens
  26. 20 BCD Seconds Tens
  27. 40 BCD Seconds Tens
  28. Bi-Phase Mark Phase Correction Bit (0)
  29. Bit 0 of 4th Binary Group (User Bits)
  30. Bit 1 of 4th Binary Group (User Bits)
  31. Bit 2 of 4th Binary Group (User Bits)
  32. Bit 3 of 4th Binary Group (User Bits)
  33. 1 BCD Minutes Units
  34. 2 BCD Minutes Units
  35. 4 BCD Minutes Units
  36. 8 BCD Minutes Units
  37. Bit 0 of 5th Binary Group (User Bits)
  38. Bit 1 of 5th Binary Group (User Bits)
  39. Bit 2 of 5th Binary Group (User Bits)
  40. Bit 3 of 5th Binary Group (User Bits)
  41. 10 BCD Minutes Tens
  42. 20 BCD Minutes Tens
  43. 40 BCD Minutes Tens
  44. Binary Group Flag Bit (0)
  45. Bit 0 of 6th Binary Group (User Bits)
  46. Bit 1 of 6th Binary Group (User Bits)
  47. Bit 2 of 6th Binary Group (User Bits)
  48. Bit 3 of 6th Binary Group (User Bits)
  49. 1 BCD Hours Units
  50. 2 BCD Hours Units
  51. 4 BCD Hours Units
  52. 8 BCD Hours Units
  53. Bit 0 of 7th Binary Group (User Bits)
  54. Bit 1 of 7th Binary Group (User Bits)
  55. Bit 2 of 7th Binary Group (User Bits)
  56. Bit 3 of 7th Binary Group (User Bits)
  57. 10 BCD Hours Tens
  58. 20 BCD Hours Tens
  59. Unassigned Address Bit 58 (0)
  60. Binary Group Flag Bit (0)
  61. Bit 0 of 8th Binary Group (User Bits)
  62. Bit 1 of 8th Binary Group (User Bits)
  63. Bit 2 of 8th Binary Group (User Bits)
  64. Bit 3 of 8th Binary Group (User Bits)
  65. Bit 0 - Binary Sync Word (0)
  66. Bit 1 - Binary Sync Word (0)
  67. Bit 2 - Binary Sync Word (1)
  68. Bit 3 - Binary Sync Word (1)
  69. Bit 4 - Binary Sync Word (1)
  70. Bit 5 - Binary Sync Word (1)
  71. Bit 6 - Binary Sync Word (1)
  72. Bit 7 - Binary Sync Word (1)
  73. Bit 8 - Binary Sync Word (1)
  74. Bit 9 - Binary Sync Word (1)
  75. Bit 10 - Binary Sync Word (1)
  76. Bit 11 - Binary Sync Word (1)
  77. Bit 12 - Binary Sync Word (1)
  78. Bit 13 - Binary Sync Word (1)
  79. Bit 14 - Binary Sync Word (0)
  80. Bit 15 - Binary Sync Word (1)
Per 80-Bit Frame, there are 32 User Binary Spare Bits, 16 Sync Bits, 31 Assigned Bits, 1 Unassigned Bit.

Any Unassigned or Unused Bits should be set to a logical zero (0) until assigned or used.


Chapter 3) Special Bit Assignments

Bit 10 - Drop Frame Flag. If certain numbers are being dropped to resolve the difference between real time and color time, a one (1) shall be recorded.

Bit 11 - Color Frame Flag. If color frame identification has been intentionally applied, a one (1) shall be recorded.

Bit 27 - "Bi-phase Mark" Phase Correction. This bit shall be put in a state so that every 80-bit word will contain an even number of logical zero's.

Bits 43 and 59 - Binary Group Flag Bits. The Binary Groups (User Bits) are intended for storage of data by the users, and the 32 bits within the 8 broups may be assigned in any manner without restriction if the character set used for the data insertion is not specified and the binary group flag bits 43 and 59 are both zero.

If an 8-bit character set is used, the binary group flag bits 43 and 59 shall be set according to the following truth table:


				Bit 43	Bit 59
Character set not specified	   0	   0
Eigh-bit character set		   1	   0
Unassigned			   0	   1
Unassigned			   1	   1
Unassigned states of the truth table cannot be used and their assignment is reserved to the SMPTE.

Note that the 16-Bit Sync word bit values are fixed as indicated above.


Please check attribution section for Author of this document! This article was written by filipg@repairfaq.org [mailto]. The most recent version is available on the WWW server http://www.repairfaq.org/filipg/ [Copyright] [Disclaimer]