| Signal | Direction | Clock Domain | Description |
|---|---|---|---|
| tod_1pps_in | IN | N/A | External bus 1-PPS input |
| tod_sec_clk_in | IN | N/A | External bus clock, used for tod_sec_in |
| tod_sec_in | IN | tod_sec_clk_in | External bus seconds serial data |
| tod_1pps_out | Output | ts_clk |
1-PPS output Asserted when the system timer’s nano-second field rolls over |
| tod_sec_clk_out | IN | N/A | Echo of external bus clock |
| tod_sec_out | IN | tod_sec_clk_in | Serial output of internal ToD seconds |