System clockThe clock generation unit provides versatile means to select the clock source and the clock speed for the CPU and the peripheral components.2.3.1 Clock sourcesThe NCF29A1 / NCF29A2 provides several clock sources, which are summarized in Table 13. Four of these clock sources (RCCLK, AUXCLK, XODIV2CLK, LPRCCLK) are based on internal oscillators.