HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 638

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

(8) Notes concerning mounting board development—handling of V
1. The standard 12 V high voltage is applied to the V
programming flash memory. The voltage at these pins also includes overshoot and noise, and
the following points should be noted to ensure that the 13 V maximum rated voltage is not
exceeded.
(a) Bypass capacitors should be inserted to eliminate overshoot and noise. These should be
(b) The V
(c) The maximum rated voltage is based on the potential of the V
Note: When the user system’s 12 V power supply is connected, attention must be paid to
positioned as close as possible to the chip’s V
1.0 µF:
0.01 µF: Bypasses high-frequency components such as induction noise.
induction noise. When designing a new board, in particular, noise may be increased by
jumper wires, etc. In this case too, the power supply waveform should be monitored
and measures taken to prevent the maximum rating from being exceeded.
this pin oscillates due to current fluctuations, etc., the voltage of the V
MD2 pins may reciprocally exceed the maximum rated voltage. Careful attention must
therefore be paid to stabilizing the reference potential.
the current capacity. A power supply with a small current capacity will not be able to
handle fluctuations in the chip’s operating voltage, resulting in voltage drops and
rises or oscillation that may make it impossible to obtain the rated operating voltage.
If the power supply has a large current capacity, or if the 12 V voltage is turned on
abruptly by means of a switch, etc., caution is required since a voltage exceeding the
maximum rating may be generated due to the inductance component of the power
supply wiring or the power supply characteristics.
Before using the power supply, check the power supply waveform to ensure that the
above problems will not arise.
PP
and mode MD2 pin wiring should be kept as short as possible to suppress
Stabilizes fluctuations in the low-frequency components, such as power
supply ripple.
629
PP
and mode MD2 pins when erasing or
PP
and mode MD2 pins.
PP
and mode MD2 pins
SS
pin. If the potential of
PP
and mode