Set the spread spectrum clocking for a clock.
Set the SSC for a clock with desired modulation frequency, spread type and modulation depth, all within their allowable range. SSC can only be enabled on clocks that have SSC support in the hardware. This message will fail if SSC is not supported by the hardware.
- Parameters
-
| hdr | TISCI header |
| device | The device ID that the clock is connected to. |
| clk | Each device has its own set of clock inputs. This indexes which clock input to modify. |
| modfreq_hz | The desired modulation frequency in Hz. The modulation period is the time required to cycle the clock nominal frequency from an initial value through all the different values along the modulation profile and back to the initial value. The modulation frequency is the inverse of the period. The minimum allowable frequency is 32 kHz and maximum is fREFCLK / 200. For example, if the fREFCLK is 25 MHz, the maximum allowable modulation frequency would be 125 kHz. |
| mod_depth | The target modulation depth in "permyriad". The modulation depth refers to the maximum variation in frequency as a percentage of the clock center frequency. The minimum modulation depth is 0.1% and the maximum is 3.1%. Modulation depth can be adjusted in 0.1% increments. |
| spread_type | The target spread type. Both center and down spread are supported. |
| enable | Enable or disable SSC. |
1.8.20