Tiny Tapeout > Tiny Tapeout Chips > Tiny Tapeout IHP 26a > 526 IHP Gate Delay Characterizer (3-Flavor)
526 IHP Gate Delay Characterizer (3-Flavor)
526 : IHP Gate Delay Characterizer (3-Flavor)
- Author: Catalin Lazar
- Description: Characterizes 3 flavors of ring oscillators (Inv1, 2, 4) with 31 stages (30 inv + 1 NAND, prime length) using a 24-bit counter.
- GitHub repository
- Open in 3D viewer
- Clock: 10000000 Hz
IHP Gate Delay Characterizer
How it works
Three 31-stage ring oscillators are implemented using specific IHP SG13G2 standard cells. A 2-bit mux selects the clock source for a 24-bit asynchronous counter. A 10ms sampling window (derived from the 10MHz system clock) captures the counter value, which is then read out in 8-bit slices.
How to test
- Set rst_n high and ui_in[0] low.
- Set ui_in[0] high to enable oscillation.
- Cycle through ui_in[2:1] to select different oscillators.
- Cycle through ui_in[4:3] to read the Low, Mid, and High bytes of the frequency on uo_out.
External hardware
No external hardware required other than the standard Tiny Tapeout demo board.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | global_en (Master Enable) | data_out[0] | unused |
| 1 | f_sel[0] (Flavor Select Bit 0) | data_out[1] | unused |
| 2 | f_sel[1] (Flavor Select Bit 1) | data_out[2] | unused |
| 3 | b_sel[0] (Byte Select Bit 0) | data_out[3] | unused |
| 4 | b_sel[1] (Byte Select Bit 1) | data_out[4] | unused |
| 5 | unused | data_out[5] | unused |
| 6 | unused | data_out[6] | unused |
| 7 | unused | data_out[7] | unused |