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CHAPTER 22 RESET FUNCTION
Table 22-1. Hardware Statuses after Reset (1/2)
Hardware
Status After Reset
Program counter (PC)
Note 1
Contents of reset vector table
(0000H, 0001H) are set.
Stack pointer (SP)
Undefined
Program status word (PSW)
02H
RAM
Data memory
Undefined
Note 2
General register
Undefined
Note 2
Port (Output latch)
00H
Port mode registers (PM0, PM2 to PM7)
FFH
Pull-up resistor option registers (PU0, PU2 to PU7)
00H
Processor clock control register (PCC)
04H
Memory size switching register (IMS)
CFH
Note 3
Memory expansion mode register (MEM)
00H
Memory expansion wait setting register (MM)
10H
Oscillation stabilization time selection register (OSTS)
04H
16-bit timer/event
counter
Timer register (TM0)
00H
Capture/compare register (CR00, CR01)
Undefined
Prescaler mode register (PRM0)
00H
Mode control register (TMC0)
00H
Output control register (TOC0)
00H
8-bit timer/event counter
Timer counters (TM50, TM51)
00H
Compare registers (CR50, CR51)
Undefined
Clock selection registers (TCL50, TCL51)
00H
Mode control register (TMC50, TMC51)
04H
Watch timer
Mode control register (WTM)
00H
Watchdog timer
Clock selection register (WDCS)
00H
Mode register (WDTM)
00H
Notes 1.
During reset input or oscillation stabilization time wait, only the PC contents among the hardware
statuses become undefined. All other hardware statuses remain unchanged after reset.
2.
When a reset is executed in the standby mode, the pre-reset status is held even after reset.
3.
Although the initial value is CFH, use the following value to be set for each version.
μ
PD780021, 780021Y, 780031, 780031Y : 42H
μ
PD780022, 780022Y, 780032, 780032Y : 44H
μ
PD780023, 780023Y, 780033, 780033Y : C6H
μ
PD780024, 780024Y, 780034, 780034Y : C8H
μ
PD78F0034, 78F0034Y
: Value for mask ROM versions