
HD404889/HD404899/HD404878/HD404868 Series
38
Table 1 (1) Initial Values after MCU Reset
Item
Abbr.
Initial
value
Contents
Program counter
(PC)
$0000
Program executed from ROM start address
Status flag
(ST)
1
Branching by conditional branch instruction enabled
Stack pointer
(SP)
$3FF
Stack level is 0
Interrupt
Interrupt enable flag
(IE)
0
All interrupts disabled
flags/ mask Interrupt request flag
(IF)
0
No interrupt requests
Interrupt mask
(IM)
1
Interrupt requests masked
I/O
Port data register
(PDR)
All bits 1 "1" level output possible
Data control registers
(DCD0 to 2) All bits 0 Output buffer off (high impedance)
Data control registers
(DCR0 to 7,
DCR80,
DCR81)
All bits 0
Port mode register 0
(PMR0)
--00
See port mode register 0 section
Port mode register 1
(PMR1)
0000
See port mode register 1 section
Port mode register 2
(PMR2)
0000
See port mode register 2 section
Port mode register 3
(PMR3)
0000
See port mode register 3 section
Port mode register 4
(PMR4)
0000
See port mode register 4 section
Edge detection select
register
(ESR)
--00
See edge detection select register section
Timers
Timer mode register A
(TMA)
0000
See timer mode register A section
Timer mode register B1
(TMB1)
0000
See timer mode register B1 section
Timer mode register B2
(TMB2)
-000
See timer mode register B2 section
Timer mode register C1
(TMC1)
0000
See timer mode register C1 section
Timer mode register C2
(TMC2)
-0--
See timer mode register C2 section
Timer mode register D1
(TMD1)
0000
See timer mode register D1 section
Timer mode register D2
(TMD2)
-000
See timer mode register D2 section
Prescaler S
(PSS)
$000
Prescaler W
(PSW)
$00
Timer/counter A
(TCA)
$00
Timer/counter B
(TCB)
$00
Timer/counter C
(TCC)
$00
Timer/counter D
(TCD)
$00
Timer write register B
(TWBU,L)
$X0
Timer write register C
(TWCU,L)
$X0
Timer write register D
(TWDU,L)
$X0