DWD preload
11 0
DWD down counter
24 0
=0
To RESET
DWD ctrl
31 0
DWD hardwired
31 0
code
=
RTIWDKEY
15 0
Compare
15 0
16 bit out to 2
WD Finite State Machine
KEY [1:0]
Discharge
Reset
Suspend
logic
RTICLK
nTRST
RTIDWDPRLD
RTIDWDCTRL
RTIDWDCNTR
time
RTICPUC0
NTUx
UC0 reset
by NTU edge
UC0 reset
by CPUC0
compare match
switch to internal
timebase
RTIUC0
missing NTU pulse
Module Operation
591
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Real-Time Interrupt (RTI) Module
Figure 17-7. Missing NTUx Signal Example
17.2.5 Digital Watchdog (DWD)
The digital watchdog (DWD) is an optional safety diagnostic which can detect a runaway CPU and
generate either a reset or NMI (non-maskable interrupt) response. It generates resets or NMIs after a
programmable period, or if no correct key sequence was written to the RTIWDKEY register.
illustrates the DWD.
Figure 17-8. Digital Watchdog