NXP Semiconductors MPC5606S - SWT Counter Output Register (SWT_CO)

Safety
MPC5606S Microcontroller Reference Manual, Rev. 7
126 Freescale Semiconductor
4.2.5.7 SWT Counter Output Register (SWT_CO)
The SWT Counter Output (SWT_CO) register is a read only register that shows the value of the internal
down counter when the SWT is disabled.
4.2.5.8 SWT Service Key Register (SWT_SK)
The SWT Service Key (SWT_SK) register holds the previous (or initial) service key value. This register
is read-only if either the SWT_CR[HLK] or SWT_CR[SLK] bits are set.
Address: Base + 0x0014 Access: User read-only
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R CNT[31:16]
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R CNT[15:0]
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 4-17. SWT Counter Output Register (SWT_CO)
Table 4-12. SWT_CO Register field descriptions
Field Description
CNT Watchdog Count. When the watchdog is disabled (SWT_CR[WEN]=0) this field shows the value of the
internal down counter. When the watchdog is enabled the value of this field is 0x0000_0000. Values in this
field can lag behind the internal counter value for up to six system plus eight counter clock cycles.
Therefore, the value read from this field immediately after disabling the watchdog may be higher than the
actual value of the internal counter.
Address: Base + 0x0018 Access: User write-only
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
W SK
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 4-18. SWT Service Key Register (SWT_SK)
Table 4-13. SWT_SK field descriptions
Field Description
SK Service Key.This field is the previous (or initial) service key value used in keyed service mode. If
SWT_CR[KEY] is set, the next key value to be written to the SWT_SR is (17
× SK + 3) mod 2
16
.