SPRUIU1D July 2020 – December 2024 DRA821U , DRA821U-Q1
The time stamp value is a 64-bit value that increments on each CPTS_RFT_CLK rising edge when CPTS_EN bit is set to 1h. When CPTS_EN bit is cleared to 0h, the time stamp value is reset to 0h.
64-bit mode is selected when CPSW_CPTS_CONTROL_REG[5] MODE bit set to 1h.
For test purposes, the time stamp value can be written via the time stamp load function (CPSW_CPTS_TS_LOAD_EN_REG, CPSW_CPTS_TS_LOAD_VAL_REG, and CPSW_CPTS_TS_LOAD_HIGH_VAL_REG registers). The CPSW_CPTS_TS_ADD_VAL_REG feature is included to allow 1ns timestamp operations with an CPTS_RFT_CLK rate less than 1Ghz. Table 12-1750 shows the CPTS_RFT_CLK and CPSW_CPTS_TS_ADD_VAL_REG values for 1ns operations.
| CPTS_RFT_CLK (MHz) | CPSW_CPTS_TS_ADD_VAL_REG[2-0] ADD_VAL |
|---|---|
| 1000 MHz | 0 |
| 500 MHz | 1 |
| 333.33 MHz | 2 |
| 250 MHz | 3 |
| 200 MHz | 4 |
| 166.66 MHz | 5 |
| 142.85714 MHz | 6 |
| 125 MHz | 7 |