NEC mPD780852 Series, Preliminary User'S Manual

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CHAPTER 2 PIN FUNCTION
Preliminary User’s Manual U14581EJ3V0UM00
2.2.8 P81 to P87 (Port 8)
These pins constitute a 7-bit input/output port. In addition, they also function as segment signal output pins of the
LCD controller/driver.
The following operation modes can be specified in 1-bit units.
(1) Port mode
In this mode, P81 to P87 function as a 7-bit input/output port. They can be set in the input or output port in 1-
bit units with the port mode register 8 (PM8).
(2) Control mode
In this mode, P81 to P87 function as segment signal output pins (S13 to S19) of the LCD controller/driver.
2.2.9 P90 to P97 (Port 9)
These pins constitute an 8-bit input/output port. In addition, they also function as segment signal output pins of
the LCD controller/driver.
The following operation modes can be specified in 1-bit units.
(1) Port mode
In this mode, P90 to P97 function as an 8-bit input/output port. They can be set in the input or output port in
1-bit units with the port mode register 9 (PM9).
(2) Control mode
In this mode, P90 to P97 function as segment signal output pins (S5 to S12) of the LCD controller/driver.
2.2.10 COM0 to COM3
These pins output common signals from the LCD controller/driver during 4-time division drive in 1/3 bias mode
(COM0 to COM3 outputs).
2.2.11 V
LCD
This pin supplies a voltage to drive an LCD.
2.2.12 AV
REF
This is an A/D converter reference voltage input pin. This pin also functions as an analog power supply pin (AV
DD
).
Supply power to this pin when the A/D converter is used.
When A/D converter is not used, connect this pin to V
DD0
.
2.2.13 AV
SS
This is a ground voltage pin of A/D converter. Always use the same voltage as that of the V
SS0
pin even when
an A/D converter is not used.
2.2.14 RESET
This is a low-level active system reset input pin.
2.2.15 X1 and X2
Crystal resonator connect pins for main system clock oscillation.
When using an external clock supply, input it to X1 and its inverted signal to X2.