SLLSFU1A December 2023 – July 2024 MCF8315C
PRODMIX
Speed loop accuracy of MCF8315C over the operating temperature range can be improved by providing a more accurate clock reference on EXT_CLK pin as shown in Figure 6-53. EXT_CLK will be used to calibrate the internal clock oscillator - this will help match the accuracy of the internal clock oscillator to that of the external clock. External clock source can be selected by configuring CLK_SEL to 11b and setting EXT_CLK_EN to 1b. The external clock source frequency can be configured through EXT_CLK_CONFIG.
External clock is optional and can be used when higher clock accuracy is needed. MCF8315C will always power up using the internal oscillator in all modes.