35.10.3 External Clock

Figure 35-2. External Clock Waveform

Table 35-12. External Clock Specifications
Symbol	Description	Min.	Typ. ✝	Max.	Units
f_CLCL^*	Clock frequency	—	—	20	MHz
T_CLCL	Clock period	50	—	—	ns
t_CHCX	High time	—	40	—	%
t_CLCX	Low time	—	40	—	%
ΔT_CLCL	Change in period from cycle to cycle time	—	20	—	%
✝ Data in the “Typ.” column is measured at T_A = 25°C and V_DD = 3.0V unless otherwise specified. These parameters are not tested and are for design guidance only. * The system clock is derived from the external clock and must be prescaled to comply with the system clock timing characterstics.