TMS570LC4357: OSC Fault Detect

Hello,

The LPO clock detect module consists of a clock monitor (CLKDET) and an internal low-power oscillator (LPO). The LPO is comprised of two oscillators: HF LPO and LF LPO.

After power-on reset is released, the CLKDET keeps monitoring the OSCIN all the time. In case the OSCIN frequency falls out of the valid range, the CLKDET flags this condition in the global status register (GLBSTAT bit 0: OSC FAIL) and switches all clock domains sourced by OSCIN to the HFLPO.

Yes, it will switch to HF LPO if the oscillator goes out of range after reaching the default clock.

No, there is no error output to nERROR when OSC fails. ESM doesn't monitor the crystal oscillator failure detection circuit.

QJ,

That is not correct.

An oscillator fault is signaled to the ESM group 1 channel 11. As a result of this being an ESM group 1 error, there is no reaction to this error by default. The application can configure the ESM module to drive the nERROR pin and/or generate an interrupt to the CPU when this fault is signaled.

Regards, Sunil