Renesas Single-Chip Microcomputer M34519T-MCU - Manual (Page 28)

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To change a clock frequency, attach the necessary parts to the included oscillator circuit board OSC-2.
For details about the oscillation circuit constant, consult your oscillator manufacturer.
4.7 Real-time Capability of the Timer
The M34519T-MCU has its internal clock operating even during emulation, so that the timer values
keep changing.
Examples: (1) When single-stepping the program
(2) When registers or internal RAM are referenced or modified
4.8 Pullup Transistor Control
Because the M34519T-MCU has an emulation circuit present in ports P0 and P1, you cannot use the
MCU's internal pullup transistors. Therefore, the M34519T-MCU controls on/off of external pullup
resistors by decoding the pullup control register transfer instructions (TPU0A and TPU1A).
The M34519T-MCU contains 150k Ω pullup resistors for use with the 4518, 4519, 4583 and 4584
Groups. If these pullup resistors need to be changed, replace the RA5 resistor array.
4.6 System Clock
Depending on the supply voltage and operation mode, use one of the following frequencies listed in
Table 4.3.
Table 4.3 M34519T-MCU operating frequencies
Voltage
5 V
3 V
Mode
Divide-by-8
Divide-by-4
Divide-by-2
Through
Divide-by-8
Divide-by-4
Divide-by-2
Through
Frequency
6.0 MHz or less
6.0 MHz or less
4.4 MHz or less