RTI Control Registers
466
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Real-Time Interrupt (RTI) Module
13.3.31 RTI Watchdog Key Register (RTIWDKEY)
This register must be written with the correct written key values to serve the watchdog. This register is
shown in
and described in
.
NOTE:
It has to be taken into account that the write to the RTIWDKEY register takes 3 VCLK cycles.
Figure 13-42. RTI Watchdog Key Register (RTIDWDKEY) [offset = 9Ch]
31
16
Reserved
R-0
15
0
WDKEY
R/WP-A35Ch
LEGEND: R/W = Read/Write; R = Read only; WP = Write in privileged mode only; -
n
= value after reset
Table 13-32. RTI Watchdog Key Register (RTIDWDKEY) Field Descriptions
Bit
Field
Value
Description
31-16
Reserved
0
Reads return 0 and writes have no effect.
15-0
WDKEY
0-FFFFh
Watchdog key. These bits provide the key sequence location.
Reads returns the current WDKEY value.
A write of E51Ah followed by A35Ch in two separate write operations defines the key sequence
and reloads the DWD. Writing any other value causes a reset or NMI, as shown in
.
Writing any other value will cause the WDKEY to reset to A35Ch.
Table 13-33. Example of a WDKEY Sequence
Step
Value Written to WDKEY
Result
1
A35Ch
No action
2
A35Ch
No action
3
E51Ah
WDKEY is enabled for reset or NMI by next A35Ch.
4
E51Ah
WDKEY is enabled for reset or NMI by next A35Ch.
5
E51Ah
WDKEY is enabled for reset or NMI by next A35Ch.
6
A35Ch
Watchdog is reset.
7
A35Ch
No action
8
E51Ah
WDKEY is enabled for reset or NMI by next A35Ch.
9
A35Ch
Watchdog is reset.
10
E51Ah
WDKEY is enabled for reset or NMI by next A35Ch.
11
2345h
System reset or NMI; incorrect value written to WDKEY.