SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
For validated set of parameters that can be programmed to PLLs, please refer to the device-specific Datasheet.
Initially, the device powers up in PLL bypass mode. The bypass mux is a glitch free mux and is located outside the PLL module. PLL_EXTBYPASS bit controls the bypass mux section. During Power-up, the bypass mux defaults to select FREF clock (PLL clock bypass mode).
During boot, WKUP_DMSC0 ROM programs the MCU_PLL0 to a valid frequency based on the crystal frequency and BOOTMODE pin settings. WKUP_DMSC0 then waits for PLL to be locked by checking the PLL LOCK status bit. WKUP_DMSC0 ROM programs PLL_EXTBYPASS bit to ‘0’ to disable the bypass mode to propagate MCU_PLL0 clock to WKUP_PLLCTRL0. At this point WKUP_DMSC0 brings MCU_R5FSS out of reset to complete the reset of the boot process. R5FSS software configures the remaining PLLs and bring them out of bypass mode.