Various external clock inputs/outputs are needed to drive the device. Summary of these input clock signals is as follows:
- MCU_OSC0_XO/MCU_OSC0_XI — external main crystal interface pins connected to the internal high-frequency oscillator (HFOSC0), which is the default clock source for internal reference clock HFOSC0_CLKOUT.
- OSC1_XO/OSC1_XI — external main crystal interface pins connected to the internal high-frequency oscillator (HFOSC1), which is the default clock source for internal reference clock HFOSC1_CLKOUT. OSC1 is used as the source for the audio bit clocks and should be 24.576MHz.
- WKUP_LFOSC0_XO/WKUP_LFOSC0_XI — external crystal interface pins connected to internal low-frequency oscillator (WKUP_LFOSC0), which sources optional 32768 Hz reference clock.
- General purpose clock inputs
- MCU_EXT_REFCLK0 — optional external system clock.
- EXT_REFCLK1 — optional external system clock, can be used as a McASP high-frequency input clock when configured to operate as an input.
- External audio reference clock inputs/outputs
- AUDIO_EXT_REFCLK[2:0] — optional McASP high-frequency input clocks when configured to operate as an input.
For more information about Input clock interfaces, see Clocking section in Device Configuration chapter in the device TRM.