To reduce production board costs and application development time, all F28004x devices contain two independent internal oscillators, referred to as INTOSC1 and INTOSC2. By default, both oscillators are enabled at power up. INTOSC2 is set as the source for the system reference clock (OSCCLK) and INTOSC1 is set as the backup clock source. INTOSC1 can also be manually configured as the system reference clock (OSCCLK). Table 5-22 provides the electrical characteristics of the internal oscillators to determine if this module meets the clocking requirements of the application.