Signal Conflict (Reset Pin) - NEC PD789860 User Manual

<RESET pin>
If the reset signal of the dedicated flash programmer is connected to the RESET pin connected to the reset signal
generator on-board, a signal conflict occurs. To prevent this, isolate the connection with the reset signal generator.
If the reset signal is input from the user system in the EEPROM programming mode, a normal programming
operation cannot be performed.
programmer.
µ
PD78E9860A, 78E9861A
RESET
<Port pins>
µ
When the PD78E9860A and 78E9861A enter the EEPROM programming mode, all the pins other than those
that communicate with the flash programmer are in the same status as immediately after reset.
If the external device does not recognize initial statuses such as the output high impedance status, therefore,
connect the external device to V
<Oscillator>
• In µ
PD78E9860A
When using the on-board clock, connect X1 and X2 as required in the normal operation mode.
When using the clock output of the flash programmer, connect it directly to X1, disconnecting the main resonator
on-board, and leave the X2 pin open.
• In µ
PD78E9861A
Connect CL1 and CL2 as required in the normal operation mode, and connect the clock output of the flash
programmer to the P03 pin.
<Power supply>
To use the power output from the flash programmer, connect the V
the V pin to GND of the flash programmer.
SS
To use the on-board power supply, make connections that accord with the normal operation mode. However,
because the voltage is monitored by the flash programmer, be sure to connect VDD of the flash programmer.
166
µ
CHAPTER 17 PD78E9860A, 78E9861A
Therefore, do not input other than reset signals from the dedicated flash
Figure 17-7. Signal Conflict (RESET Pin)
Connection pin of
Signal conflict
Reset signal generator
The signal output by the reset signal generator and the signal output from
the dedicated flash programmer conflict in the EEPROM programming
mode, so isolate the signal of the reset signal generator.
or V via a resistor.
DD SS
User's Manual U14826EJ5V0UD
dedicated flash
programmer
Output pin
pin to VDD of the flash programmer, and
DD