ISD94100 Series Technical Reference Manual
Sep 9, 2019
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If current CNTDAT (WWDT_CNT[5:0]) is larger than CMPDAT (WWDT_CTL[21:16]) and user
writes 0x00005AA5 to the WWDT_RLDCNT register, the WWDT reset system signal will be
generated immediately to cause chip reset also. The waveform of WWDT reload counter when
CNTDAT > CMPDAT is shown in Figure 6.10-4.
WWDT_CLK
WWDTIF
(WWDT_STATUS[0])
WWDTRF
(WWDT_STATUS[1])
T
WWDT
WWDTVAL
20
1F
Note :
PSCSEL (WWDT_CTL[11:8]) = 0x0,
CMPDAT (WWDT_CTL[21:16]) = 0x10
1E 1D 3F
3E
Write 0x00005AA5 to
WWDT_RLD
3D 3C
Figure 6.10-4 WWDT Reload Counter When CNTDAT > CMPDAT
When WWDTIF (WWDT_STATUS[0]) is generated, user must reload WWDT counter value to 0x3F
by writing 0x00005AA5 to WWDT_RLDCNT register, and also to prevent WWDT counter value
reached to 0 and generate WWDT reset system signal to info system reset. Figure 6.10-5 shows
the waveform of WWDT reload counter when CNTDAT < CMPDAT and Figure 6.10-6 shows
WWDT generate reset system signal (WWDTRF) if user doesn’t write 0x00005AA5 to WWDT_RLD
before WWDT counter value reach to 0.
Write 0x00005AA5 to
WWDT_RLD
WWDT_CLK
WWDTIF
(WWDT_STATUS[0])
WWDTRF
(WWDT_STATUS[1])
T
WWDT
WWDTVAL
0F 0E 3F 3E 3D
Note :
PSCSEL (WWDT_CTL[11:8]) = 0x0,
CMPDAT (WWDT_CTL[21:16]) = 0x10
11 10
3C 3B 3A