HD64F38024HV Datasheet, PDF (141/684 Pages) Renesas Technology Corp – Hardware Manual Renesas 8-Bit Single-Chip Microcomputer H8 Family/H8/300L Super Low Power Series

Section 4 Clock Pulse Generators
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 V_CC 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 V_CC 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.
Rev. 8.00 Mar. 09, 2010 Page 119 of 658
REJ09B0042-0800