HD6433044 Datasheet, PDF (639/867 Pages) Hitachi Semiconductor – Hitachi Single-Chip Microcomputer

2. 12 V is applied to the V_PP and mode MD2 pins when programming or erasing flash memory.
When these pins are pulled up to the V_CC line in normal operation, diodes should be inserted to
prevent reverse current from flowing to the V_CC line when 12 V is applied.
Note: In normal operation, if the mode MD2 pin to which 12 V is applied is to be set to 0, it
should be pulled down with a resistor.
A sample circuit is shown figure 18-32.
V_CC
V_PP pin
12 V
V_PP
V_CC
0.01 µF 1.0 µF
H8/3048F
12 V
Mode pin
MD2
mode
pin
0.01 µF 1.0 µF
Adapter board
User system
Figure 18-32 Example of Mounting Board Design
(Connection to Adapter Board—When V_PP Pin and Mode Pin Settings Are 1)
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