HD404369 Datasheet, PDF (19/117 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer

HD404369 Series
Table 1 Initial Values After MCU Reset
Item
Abbr. Initial Value Contents
Program counter
(PC)
$0000
Indicates program execution point from start
address of ROM area
Status flag
(ST)
1
Enables conditional branching
Stack pointer
(SP)
$3FF
Stack level 0
Interrupt Interrupt enable flag (IE)
0
flags/mask
Inhibits all interrupts
Interrupt request flag (IF)
0
Indicates there is no interrupt request
Interrupt mask
(IM)
1
Prevents (masks) interrupt requests
I/O
Port data register
(PDR) All bits 1 Enables output at level 1
Data control register
(DCD0- All bits 0
DCD2)
Turns output buffer off (to high impedance)
(DCD3) - - 00
(DCR0–
DCR6,
DCR8,
DCR9)
All bits 0
(DCR7) - 000
Port mode register A (PMRA) 0000
Refer to description of port mode register A
Port mode register B (PMRB2– 000
bits 2–0
PMRB0)
Refer to description of port mode register B
Port mode register C (PMRC) 00 - 0
Refer to description of port mode register C
Timer/count- Timer mode register A
ers, serial
interface
(TMA)
0000
Refer to description of timer mode register A
Timer mode register B1 (TMB1) 0000
Refer to description of timer mode register B1
Timer mode register B2 (TMB2) - 000
Refer to description of timer mode register B2
Timer mode register C (TMC) 0000
Refer to description of timer mode register C
Serial mode register (SMR) 0000
Refer to description of serial mode register
Prescaler S
(PSS) $000
—
Prescaler W
(PSW) $00
—
Timer counter A
(TCA) $00
—
Timer counter B
(TCB) $00
—
Timer counter C
(TCC) $00
—
Timer write register B (TWBU, $X0
—
TWBL)
Timer write register C (TWCU, $X0
—
TWCL)
Octal counter
000
—
17