SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
A dedicated coarse clock loss logic checks the XTAL clock against the RC CLK continuously to detect if the XTAL clock is toggling.
When this module detects a clock error on XTAL Clock, the error signal is routed to the GCM’s to activate the Limp mode. When the limp mode is activated, all the GCM switch to RCCLK (clk source #5). This ensures the CPU continues to operate even if the XTAL Clock fails and can take the system to a safe state.
Switch to Limp mode feature is not enabled by default. The feature needs to be explicitly enabled by S/W by TOP_RCM.LIMP_MODE_EN.XTALCLK_LOSS_EN
In addition, error on DCC0 and CORE_PLL Phase lock loss can also trigger Limp-mode for added safety. This feature can be enabled by the bits TOP_RCM.LIMP_MODE_EN.COREPLL_LOSS_EN and TOP_RCM.LIMP_MODE_EN.DCC0_ERROR_EN