487 Linear Timecode (LTC) generator
487 : Linear Timecode (LTC) generator
- Author: Thomas Flummer
- Description: Timecode generator for audio video syncronization
- GitHub repository
- Open in 3D viewer
- Clock: 12000000 Hz
How it works
Multiple counters to maintain time and framecount, with serial output of the LTC (80 bit frames, biphase mark code)
How to test
The project should have 12 MHz clock signal applied and after reset, will start out with a 00:00:00:00 timecode and starts to count.
Framerate is controlled by the ui[2] and ui[3]
| ui[3] | ui[2] | Framerate | Comment |
|---|---|---|---|
| 0 | 0 | 24 | |
| 0 | 1 | 25 | |
| 1 | 0 | 29.97 | Not implemented |
| 1 | 1 | 30 |
External hardware
This should work with the audio PMOD connected to the bidirectional port, to give levels useable for audio gear.
If testing with logic analyzer or similar, uio[7] can be directly connected. The signal is a digital signal.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | |||
| 1 | |||
| 2 | FRAMERATE_0 | ||
| 3 | FRAMERATE_1 | ||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 | LTC_OUT |