12.5.3 Main Clock Control C

Name: MCLKCTRLC
Offset: 0x02
Reset: 0x00
Property: Configuration Change Protection

Bit 76543210 
     CFDSRC[1:0]CFDTSTCFDEN 
Access R/WR/WR/WR/W 
Reset 0000 

Bits 3:2 – CFDSRC[1:0] Clock Failure Detection Source

This bit field controls which clock source to monitor when the Clock Failure Detection Enable (CFDEN) bit is ‘1’.
Note: This bit field is read-only when the CFDEN bit is ‘1’, and both the Clock Failure Detection (CFD) interrupt enable bit and Interrupt Type (INTTYPE) bit in the Main Clock Interrupt Control (CLKCTRL.MCLKINTCTRL) are ‘1’. This bit will remain read-only until a System Reset occurs.
ValueNameDescription
0x0 SYS Main Clock
0x1 XOSCHF External High-Frequency Oscillator
0x2 XOSC32K External 32.768 kHz Oscillator
Other - Reserved

Bit 1 – CFDTST Clock Failure Detection Test

This bit controls testing of the Clock Failure Detection (CFD) functionality.

Writing a ‘0’ to this bit will clear the bit, and the ongoing CFD test fail condition.

Writing a ‘1’ to this bit will set the bit and force a CFD fail condition.

ValueDescription
0 No ongoing test of the CFD functionality
1 A CFD fail condition has been forced

Bit 0 – CFDEN Clock Failure Detection Enable

This bit controls whether Clock Failure Detection (CFD) is enabled or not.

Note: This bit is read-only when this bit is ‘1’, and both the Clock Failure Detection (CFD) interrupt enable bit and Interrupt Type (INTTYPE) bit in the Main Clock Interrupt Control (CLKCTRL.MCLKINTCTRL) are ‘1’. This bit will remain read-only until a System Reset occurs.
ValueDescription
0 CFD is disabled
1 CFD is enabled