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4 system clock, 5 real-time capability of timer, 6 power-down mode – Renesas MCU Board for PC4400 Emulator System M34282T5-OPT User Manual

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5.4 System Clock

Depending on how the instruction clock is set, use the M34282T5-OPT in the range of frequencies
listed in table 5.2.

When the instruction clock is set to STCK = f(X

IN

) and the system clock frequency is over 500 kHz,

the emulator may not work properly.

Table 5.2 Operating frequencies of the M34282T5-OPT

* To change the system clock frequency, change the clock frequency of the oscillator circuit board

OSC-2. For details about the oscillation circuit constant, consult your oscillator manufacturer.

5.5 Real-time Capability of Timer

As the evaluation MCU is active even when program execution is stopped or when a command is
executed, its timer values are modified.

Examples:

(1) When single-stepping instructions
(2) After program execution stopped

5.6 Power-down Mode

Although the M34282T5-OPT can execute a program using the POF instruction, there are precau-
tions and restrictions listed in Table 5.3.

Table 5.3 Precautions for power-down mode.

Voltage

3 V

Instruction clock

STCK = f(X

IN

)/8

STCK = f(X

IN

)

Frequency

4.0 MHz or less

500 kHz or less

Description

Although SAFE and ERROR LEDs of the PC4000E light up in the power-down mode, it is not
an error condition.

Do not use the POF instruction when single-stepping a program. The POF instruction can not
be executed correctly when stepped through.

No debug command of emulator debugger RTT72 can be executed. In the power-down mode,
execute the debug command after resuming by the key-on wakeup function.

The real-time trace result of the area including the POF instruction cannot be displayed
normally.

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