CHAPTER 16 RESET FUNCTION
Table 16-1. Hardware Status After Reset (1/2)
Hardware
Status After Reset
Program counter (PC)Note 1
The contents of reset
vector tables (0000H
and 0001H) are set.
Stack pointer (SP)
Program status word (PSW)
RAM
Undefined
02H
Data memory
UndefinedNote 2
UndefinedNote 2
00H
General-purpose register
Port (P0 to P3, P5, P7) (Output latch)
Port (P8, P9) (Output latch)Note 3
00H
Port mode register (PM0 to PM3, PM5, PM7)
Port mode register (PM8, PM9)Note 3
FFH
FFH
Pull-up resistor option register (PU0, PUB2, PUB3, PUB7)
00H
Pull-up resistor option register (PUB8Note 3, PUB9Note 3
Processor clock control register (PCC)
Suboscillation mode register (SCKM)
)
00H
02H
00H
Subclock control register (CSS)
00H
Oscillation stabilization time select register (OSTS)
04H
16-bit timer
Timer counter (TM90)
0000H
FFFFH
00H
Compare register (CR90)
Control register (TMC90)
Capture register (TCP90)
Undefined
00H
8-bit timer
Timer counter (TM50, TM60)
Compare register (CR50, CR60, CRH60)
Mode control register (TMC50, TMC60)
Mode control register (WTM)
Undefined
00H
Watch timer
00H
Watchdog timer
Clock select register (WDCS)
00H
Mode register (WDTM)
00H
Serial interface
Serial operation mode register (CSIM20)
Asynchronous serial interface mode register (ASIM20)
Asynchronous serial interface status register (ASIS20)
Baud rate generator control register (BRGC20)
Transmit shift register (TXS20)
00H
00H
00H
00H
FFH
Receive buffer register (RXB20)
A/D conversion result register (ADCR0)
Mode register (ADM0)
Undefined
0000H
00H
A/D converter
Analog input channel specification register (ADS0)
00H
Notes 1. During reset input and oscillation stabilization time wait, only the PC contents among the hardware
statuses become undefined. All other hardware remains unchanged after reset.
2. The post-reset values are retained in the standby mode.
3. µPD789426, 789436 Subseries only
User’s Manual U15075EJ1V0UM00
289
NEC [ NEC ]
