HD404054 Datasheet, PDF (16/103 Pages) Hitachi Semiconductor – HMCS400-series microcomputers designed to increase program productivity with large-capacity memory

HD404054 Series/HD404094 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
Inhibits all interrupts
flags/mask 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 Turns output buffer off (to high impedance)
DCD2)
(DCR0– All bits 0
DCR4)
Port mode register A (PMRA) - - 00 Refer to description of port mode register A
Port mode register B (PMRB) - - - 0 Refer to description of port mode register B
Port mode register C
bits 3, 2, 1
(PMRC3, 000 -
PMRC2,
PMRC1)
Refer to description of port mode register C
Detection edge select (ESR2) 00 - -
register 2
Disables edge detection
Timer/
Timer mode register A (TMA) - 000 Refer to description of timer mode register A
counters, Timer mode register C1 (TMC1) 0000 Refer to description of timer mode register C1
serial
Timer mode register C2 (TMC2) - 000 Refer to description of timer mode register C2
interface Timer mode register D1 (TMD1) 0000 Refer to description of timer mode register D1
Timer mode register D2 (TMD2) 0000 Refer to description of timer mode register D2
Serial mode register 1A (SM1A) 0000 Refer to description of serial mode register 1A
Serial mode register 1B (SM1B) - - X0 Refer to description of serial mode register 1B
Prescaler S
(PSS) $000 —
Timer counter A
(TCA) $00
—
Timer counter C
(TCC) $00
—
Timer counter D
(TCD) $00
—
Timer write register C (TWCU, $X0
—
TWCL)
Timer write register D (TWDU, $X0
—
Octal counter
TWDL) 000
—
Comparator Compare enable
register
(CER) 0 - 00 Refer to description of voltage comparator
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