20.4.2 Enabling and Disabling the DMT Module

Because of the nature of the Deadman Timer, the module cannot be enabled or disabled using a PMD register bit. Instead, enable the Deadman Timer by setting the CFGCON2.DMTEN config register bit or the DMTCON.ON register bit. Once enabled, the DMT cannot be disabled without resetting the device.

If the DMTEN Configuration bit in the CFGCON2 fuse register is set, the DMT is always enabled. The ON CONTROL bit (DMTCON[15]) in the DMTCON register will reflect this by reading a ‘1’. In this mode, the ON bit (DMTCON[15]) cannot be cleared in the software. To disable the DMT, the DMTEN Configuration bit must be cleared in the CFGCON2 fuse register. When DMTEN is cleared to ‘0’ in the CFGCON2, the DMT is disabled in hardware.

Software can enable the DMT by setting the ON bit in the DMTCON register. However, for software control, the DMTEN Configuration bit in the CFGCON2 fuse register must be set to ‘0’.