218
CHAPTER 16 RESET FUNCTION
User’s Manual U15104EJ2V0UD
7
0
6
0
5
0
4
0
3
0
2
0
1
VM45 POCM
Symbol
POCS
After reset
Retained
Note
R/W
R&Reset
Address
FF1BH
0
16.2 Power Failure Detection Function
If reset is effected by means of power-on clear, bit 0 (POCM) of the POC status register (POCS) is set to 1. If
reset is effected by the RESET pin or the watchdog timer, however, POCM holds the previous status.
A power failure status can be detected by detecting this POCM after reset by power-on clear has been cleared
(after program execution has been started from address 0000H).
Figure 16-5. Format of POC Status Register (POCS)
POCM
Detection of power-on clear occurrence status
0
Power-on clear does not occur
1
Note
Reset is effected by power-on clear
Note
The value of this register is set to 03H only when reset is effected through power-on clearing. It is
not reset by the RESET pin or watchdog timer.
Remark
The values of the special function registers, other than POCS and PLLUL, at power-on clear are
the same as the values following a reset by the RESET pin or watchdog timer (see Table 16-1).
Содержание mPD178053
Страница 2: ...2 User s Manual U15104EJ2V0UD MEMO ...