SLAU846A June 2023 – October 2023 MSPM0G1105 , MSPM0G1106 , MSPM0G1107 , MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G3105 , MSPM0G3105-Q1 , MSPM0G3106 , MSPM0G3106-Q1 , MSPM0G3107 , MSPM0G3107-Q1 , MSPM0G3505 , MSPM0G3505-Q1 , MSPM0G3506 , MSPM0G3506-Q1 , MSPM0G3507 , MSPM0G3507-Q1
If an application requires high clocking accuracy for high-frequency peripherals, the best accuracy is achieved by using an external high-frequency crystal with the HFXT and sourcing the MCLK tree directly from HFCLK. By sourcing the MCLK directly from HFCLK, the bus clock to all peripherals in PD1 and PD0 will be the HFCLK.
Crystal frequencies up to 48 MHz are supported by the HFXT, but because PD0 peripherals using ULPCLK are limited to 40 MHz, 40 MHz is the highest crystal frequency supported to run the PD1 and PD0 peripherals at the same frequency. If a 48-MHz crystal is used, PD1 peripherals and the CPUCLK can run at 48 MHz directly from the crystal, but PD0 peripherals must run at MCLK/2 (24 MHz).
If precision clocking is needed for the CAN-FD controller or the ADC (for sampling window generation), and high CPU performance (high MCLK) is also required, it is also possible to source the CAN-FD controller (CANCLK) and the ADC sampling clock (ADCCLK) from HFCLK directly, asynchronous to MCLK, while running MCLK at maximum frequency using the PLL for best compute performance.