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CHAPTER 7 RESETS
■Correspondence between reset cause bits and reset causes
Figure 7.5-2 shows the configuration of the reset cause bits of the watchdog timer control register (WDTC).
Table 7.5-1 maps the correspondence between the reset cause bits and reset causes. See “Watchdog timer
control register (WDTC)” in "12.1 Overview of Watchdog Timer", for details.
Figure 7.5-2 Configuration of Reset Cause Bits (watchdog timer control register)
Watchdog timer control register (WDTC)
Address bit15 ........ bit8 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 Initial value
0000A8H(TBTC) PONR −WRST ERST SRST WTE WT1 WT0 XXXXX111B
R−RRRWWW
R : Read only
W : Write only
X : Undefined
Table 7.5-1 Correspondence between Reset Cause Bits and Reset Causes
Reset cause PONR WRST ERST SRST
Generation of power-on reset request 1 X X X
Generation of reset request due to watchdog timer overflow ∆1 ∆∆
External reset request from RST pin,
Low voltage detection reset (product with T-suffix)*1
CPU operation detection reset (product with T-suffix)*2
Clock supervisor reset
(MB90F367/T(S), MB90367/T(S))
∆∆1 ∆
Generation of software reset request ∆∆ ∆1
∆: Previous state retained
X: Undefined
*1: When the low voltage detection reset request is used, the CPUF bit of the low voltage/CPU operation detection reset
control register (LVRC) is also set to "1".
*2: When the CPU operation detection reset request is used, the CPUF bit of the low voltage/CPU operation detection reset
control register (LVRC) is also set to "1".