CHAPTER 2. PIN FUNCTIONS
20
V
DD
V
DD
V
DD
V
DD
Diode with
Small V
F
P00, RESET P00, RESET
2.5 UNUSED PIN TREATMENT
Pin
P00
P01 to P03
P10 and P12
P20 to P23
P30 to P33
P50 to P53
P60 to P63
NC
*If using the
µ
PD75P402 and the printed circuit board commonly, the NC pins should be connected directly to VSS.
2.6 NOTES ON USE OF P00 PIN AND RESET PIN
The P00 and RESET pins are provided with the test mode setting function of test mode (for IC test) which tests
the internal operation of the
µ
PD75402A in addition to the functions described in 2.2.1 and 2.2.8.
When a voltage exceeding VDD is applied to either of these pins, the test mode is set. Consequently, if noise
exceeding VDD is added even in a normal operation, the test mode is set and the normal operation may not be
continued.
For example, when wires from the P00 pin or RESET pin are long, inter-wiring noise may be added to these pins
and the pin voltage may exceed VDD, resulting in a misoperation.
Therefore, wiring should be carried out so that inter-wiring noise is suppressed as far as possible.
If it is impossible to suppress the noise, noise prevention measures by means of external parts should be taken
as shown below.
o Insert diode with small o Insert capacitor between
VF (less than 0.3 V) VDD and P00/RESET pin.
between VDD and
P00/RESET pin.
Recommended Connection Method
Connect to VSS.
With pull-up resistor Connect to VDD.
Without pull-up resistor
Connect to VSS or VDD.
With pull-up resistor
Input status: Connect to VDD.
Output status: Leave open.
Without pull-up resistor
Input status: Connect to VSS to VDD.
Output status: Leave open.
Leave open or connect directly to VSS.*