H838024 datasheet(160/697 Pages) RENESAS

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Section 4 Clock Pulse Generators

Rev. 7.00 Mar 10, 2005 page 118 of 652

REJ09B0042-0700

For example, if erroneous operation occurs with a wait time setting of 16 states, check the

operation with a wait time setting of 1,024* states or more.

If the same kind of erroneous operation occurs after a reset as after a state transition, hold the

RES

pin low for a longer period.

Note: * This figure applies to the H8/38024, H8/38024S, and H8/38024R Groups. The number of

states on the H8/38124 Group is 8,192 or more.

4.5.3

Note on Use of HD64F38024

When using the HD64F38024, the oscillators may not operate if an initial voltage of 10 mV is

applied to the VCC pin during power-on. This problem is caused by uncertainty about the state of

the oscillation control signals. It can be corrected by cutting off power and allowing the VCC pin

voltage to drop to ground potential before powering-on once again.

4.6

Notes on H8/38124 Group

When using the on-chip emulator, system clock precision is necessary for programming or erasing

the flash memory. However, the on-chip oscillator frequency can vary due to changes in

conditions such as voltage or temperature. Consequently, even if the on-chip oscillator is selected

when using the on-chip emulator, pins OSC1 and OSC2 should be connected to an oscillator, or an

external clock should be supplied. In this case, the LSI uses the on-chip oscillator when user

programs are being executed and the system clock oscillator when programming or erasing flash

memory. The process is controlled by the on-chip emulator.

H838024 Datasheet(PDF) 160 Page - Renesas Technology Corp