APPLICATION
2-48
4551 Group User’s Manual
2.7 Reset
2.7.2 Internal state at reset
Figure 2.7.4 shows the internal state at reset. The contents of timers, registers, flags and RAM other than
shown in Figure 2.7.4 are undefined, so set them to initial values.
Fig. 2.7.4 Internal state at reset
Program counter (PC) ............................................................................................
Address 0 in page 0 is set to program counter.
Interrupt enable flag (INTE) ...................................................................................
Power down flag (P) ...............................................................................................
External 0 interrupt request flag (EXF0) ................................................................
Interrupt control register V1 ...................................................................................
Interrupt control register I1 ....................................................................................
Timer 1 interrupt request flag (T1F) ......................................................................
Timer 2 interrupt request flag (T2F) ......................................................................
Watchdog timer flag (WDF) ...................................................................................
Watchdog timer enable flag (WEF) .......................................................................
Timer control register W1 ......................................................................................
Timer control register W2 ......................................................................................
Timer control register W3 ......................................................................................
Clock control register MR ......................................................................................
Carrier wave selection register C1 ........................................................................
Carrier wave output control register C2 .................................................................
Carrier wave generating control flag CR ...............................................................
LCD control register L1 ..........................................................................................
LCD control register L2 ..........................................................................................
Pull-up control register PU0 ...................................................................................
General-purpose register V2 .................................................................................
Carry flag (CY) .......................................................................................................
Register A ..............................................................................................................
Register B ..............................................................................................................
Register D ..............................................................................................................
Register E ..............................................................................................................
Data pointer X ........................................................................................................
Data pointer Y ........................................................................................................
Data pointer Z ........................................................................................................
Stack pointer (SP) ..................................................................................................
0000
000
0
(Interrupt disabled)
0
(Interrupt disabled)
000
0
(Prescaler stopped)
0
(Timer 1 stopped)
0
(Timer LC stopped)
100
0
011
1
0
(Carrier wave output disabled)
0
(LCD off)
1
(Port P2 selected)
000
0
000
0
000
0
000
0
!! !
000
0
000
0
!!
11
1
“!” represents undefined.
! !!!! !!!