The Analog Subsystem is clocked by ASYSCLK, which is a divided-down version of the PLLSYSCLK as defined by CLKDIV bits of the CCLKCTL register. The CCLKCTL register is exclusively accessible by the C28x processor. The CCLKCTL register is reset by ASYSRST, which is derived from two Analog Subsystem resets—ACIBRST and SRXRST. Therefore, while normally the C28x controls the frequency of ASYSCLK, it is possible for the Cortex-M3 software to restore the ASYSCLK to its default value by resetting the Analog Subsystem.
The ASYSCLK is shut down when the Cortex-M3 processor enters the Deep Sleep mode.