PD17225_15 Datasheet, PDF (53/86 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLER FOR SMALL GENERAL-PURPOSE INFRARED REMOTE CONTROL TRANSMITTER

µPD17225, 17226, 17227, 17228
9.3 Reset by Stack Pointer (Connect RESET and WDOUT pins)
When the value of the stack pointer reaches 6H or 7H during program execution, a low level is output to the WDOUT
pin, and the program counter is reset to 0.
If the nesting level of the interrupt or subroutine call exceeds 5 (stack over flow), or if the return instruction is executed
without correspondence between CALL and return (RET) instructions established, then regardless of a stack level of 0
(stack underflow), the program can be restarted from address 0H.
Table 9-1. Status of Each Hardware After Reset
Hardware
RESET Input During
Standby Mode
RESET Input
During Operation
Program Counter (PC)
0000H
0000H
Port
Input/output
Input
Input
Output latch
0
0
Data Memory (RAM)
General-purpose data memory
(Except DBF, port register)
Retains previous
status
Undefined
DBF
0320H
0320H
System register (SYSREG)
0
0
WR
Retains previous
Undefined
status
Control Register
Refer to Figure 11-1 Register Files
8-bit Timer
Counter (TMC)
00H
00H
Modulo register (TMM)
FFH
FFH
Remote Controller Carrier
Generator
NRZ high-level timer modulo register (NRZHTMM) Retains previous
NRZ low-level timer modulo register (NRZLTMM) ^status
Undefined
Basic Interval Timer/Watchdog Timer Counter
00H
00H
Data Sheet U12643EJ2V0DS00
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