PD17225_15 Datasheet, PDF (50/86 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLER FOR SMALL GENERAL-PURPOSE INFRARED REMOTE CONTROL TRANSMITTER

µPD17225, 17226, 17227, 17228
8.3 STOP Mode
In the STOP mode, the system clock (fX) oscillation is stopped and the program execution is stopped to minimize current
consumption.
To set the STOP mode, use the STOP instruction.
The STOP mode releasing condition can be specified by the STOP instruction operand, as shown in Table 8-4.
After the STOP mode has released, the operation is performed as follows:
<1> Resets IRQTM.
<2> Starts the basic interval timer and watchdog timer (does not reset).
<3> Resets and starts the 8-bit timer.
<4> Executes the instruction next to [STOP 8H] when the current value of the 8-bit counter coincides with
the value of the modulo register (IRQTM is set).
The µPD17225 oscillator is stopped, when the STOP instruction has been executed (i.e., in the STOP mode).
Oscillation is not resumed, until the STOP mode is released. After the STOP mode has been released, the HALT mode
is set. Set the time required to release the HALT mode by using the timer with modulo function.
The time that elapses, after the STOP mode has been released by occurrence of an interrupt, until an operation mode
is set, is shown in the following table.
8-Bit Modulo Register Set Value
(TMM)
40H
FFH
Time Required to Set Operation Mode
after STOP Mode Release
At 4 MHz
4.160 ms (64 µs × 65)
16.384 ms (64 µs × 256)
Remark Set the 8-bit modulo timer before executing STOP instruction.
Caution Do not execute an instruction that clears the interrupt request flag (IRQ×××) for which the
interrupt enable flag (IP×××) is set immediately before the STOP 8H instruction; otherwise, the
STOP mode may not be set.
Table 8-4. STOP Mode Releasing Conditions
Operand Value
1000B (08H)
Other Than Above
Releasing Conditions
When any of P0A0-P0A3 and P0B0-P0B3 pins goes low
Setting prohibited
48
Data Sheet U12643EJ2V0DS00