35 Synthesized Time-to-Digital Converter (TDC)
35 : Synthesized Time-to-Digital Converter (TDC)
- Author: Harald Pretl
- Description: Synthesized TDC based on an interleaved delay line
- GitHub repository
- Open in 3D viewer
- Clock: 50000000 Hz
- Feedback: ✅ 1
How it works
This is a simple synthesized time-to-digital converter (TDC), consisting of a delay line and parallel capture FF. Depending on __TDC_INTERLEAVED__ either a simple or an interleaved delay line is implemented.
In the TT 1x1 block size a 192-stage interleaved delay can be fitted.
How to test
Apply two signals to ui_in[0] and clk.
After capturing (rising edge of clk) the result (i.e., the time delay between rising edge of ui_in[0] and clk) can be muxed-out to uo_out[7:0] using ui_in[7:3] as byte-wise selector. ui_in[7:3]=0000 gives result byte 0, ui_in[7:3]=0001 gives result byte 1, etc.
External hardware
Two signal generators generating logical signals with a programmable delay.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | Start signal of TDC (stop signal is clk) | Result LSB | |
| 1 | Result | ||
| 2 | Result | ||
| 3 | Result | ||
| 4 | output select | Result | |
| 5 | output select | Result | |
| 6 | output select | Result | |
| 7 | output select | Result MSB |
User feedback
- mattvenn: I didn't do a full test. Just set a ~7ns delay between in0 and clock and then tested the output byte select until I found bits changing.