Uses counters to determine the number of cycles of the ring oscillator within a clock period, wich will then be sent through the UART to determine the temperature vs frecuency caracteristic.
After reset and enable are set, the ring oscillator should start and then when a START code is received by UART, a value is sent back.
| # | Input | Output |
|---|---|---|
| 0 | clk_internal | tx |
| 1 | clk_external | sum[8] |
| 2 | clk_sel | sum[10] |
| 3 | enable_inv_osc | sum[13] |
| 4 | enable_nand_osc | sum[15] |
| 5 | reset | sum[17] |
| 6 | rx | sum[19] |
| 7 | osc_sel | sum[21] |